Copyright (c) 1999 Association of Mizar Users
environ vocabulary FUNCT_2, MARGREL1, PARTIT1, BVFUNC_1, ZF_LANG, FUNCT_1, RELAT_1, BINARITH, EQREL_1, BVFUNC_2, T_1TOPSP; notation TARSKI, XBOOLE_0, SUBSET_1, MARGREL1, VALUAT_1, RELAT_1, FUNCT_1, FRAENKEL, EQREL_1, BINARITH, BVFUNC_1, BVFUNC_2; constructors BINARITH, BVFUNC_2, BVFUNC_1; clusters MARGREL1, VALUAT_1, BINARITH, FRAENKEL; requirements SUBSET, BOOLE; definitions BVFUNC_1; theorems FUNCT_1, FUNCT_2, T_1TOPSP, MARGREL1, BINARITH, BVFUNC_1, BVFUNC_2, VALUAT_1; begin ::Chap. 1 Preliminaries reserve Y for non empty set; theorem for a,b,c being Element of Funcs(Y,BOOLEAN) holds a '<' (b 'imp' c) implies a '&' b '<' c proof let a,b,c be Element of Funcs(Y,BOOLEAN); assume A1:a '<' (b 'imp' c); for x being Element of Y holds Pj((a '&' b) 'imp' c,x) = TRUE proof let x be Element of Y; A2: a 'imp' (b 'imp' c) = I_el(Y) by A1,BVFUNC_1:19; A3:Pj(a 'imp' (b 'imp' c),x) =('not' Pj(a,x)) 'or' Pj(b 'imp' c,x) by BVFUNC_1:def 11 .=('not' Pj(a,x)) 'or' (('not' Pj(b,x)) 'or' Pj(c,x)) by BVFUNC_1:def 11 .=('not' Pj(a,x) 'or' 'not' Pj(b,x)) 'or' Pj(c,x) by BINARITH:20; Pj((a '&' b) 'imp' c,x) =('not' Pj(a '&' b,x)) 'or' Pj(c,x) by BVFUNC_1:def 11 .='not' (Pj(a,x) '&' Pj(b,x)) 'or' Pj(c,x) by VALUAT_1:def 6 .=('not' Pj(a,x) 'or' 'not' Pj(b,x)) 'or' Pj(c,x) by BINARITH:9; hence thesis by A2,A3,BVFUNC_1:def 14; end; then (a '&' b) 'imp' c = I_el(Y) by BVFUNC_1:def 14; hence thesis by BVFUNC_1:19; end; theorem for a,b,c being Element of Funcs(Y,BOOLEAN) holds a '&' b '<' c implies a '<' (b 'imp' c) proof let a,b,c be Element of Funcs(Y,BOOLEAN); assume A1:a '&' b '<' c; for x being Element of Y holds Pj(a 'imp' (b 'imp' c),x) = TRUE proof let x be Element of Y; A2: (a '&' b) 'imp' c = I_el(Y) by A1,BVFUNC_1:19; A3:Pj(a 'imp' (b 'imp' c),x) =('not' Pj(a,x)) 'or' Pj(b 'imp' c,x) by BVFUNC_1:def 11 .=('not' Pj(a,x)) 'or' (('not' Pj(b,x)) 'or' Pj(c,x)) by BVFUNC_1:def 11 .=('not' Pj(a,x) 'or' 'not' Pj(b,x)) 'or' Pj(c,x) by BINARITH:20; Pj((a '&' b) 'imp' c,x) =('not' Pj(a '&' b,x)) 'or' Pj(c,x) by BVFUNC_1:def 11 .='not' (Pj(a,x) '&' Pj(b,x)) 'or' Pj(c,x) by VALUAT_1:def 6 .=('not' Pj(a,x) 'or' 'not' Pj(b,x)) 'or' Pj(c,x) by BINARITH:9; hence thesis by A2,A3,BVFUNC_1:def 14; end; then a 'imp' (b 'imp' c) = I_el(Y) by BVFUNC_1:def 14; hence thesis by BVFUNC_1:19; end; theorem for a,b being Element of Funcs(Y,BOOLEAN) holds a 'or' (a '&' b) = a proof let a,b be Element of Funcs(Y,BOOLEAN); A1:for x being Element of Y holds Pj(a 'or' (a '&' b),x) = Pj(a,x) proof let x be Element of Y; A2:Pj(a 'or' (a '&' b),x) =Pj(a,x) 'or' Pj(a '&' b,x) by BVFUNC_1:def 7 .=Pj(a,x) 'or' (Pj(a,x) '&' Pj(b,x)) by VALUAT_1:def 6; now per cases by MARGREL1:39; case Pj(a,x)=TRUE; hence thesis by A2,BINARITH:19; case A3: Pj(a,x)=FALSE; then Pj(a 'or' (a '&' b),x) =FALSE 'or' FALSE by A2,MARGREL1:45 .=FALSE by BINARITH:7; hence thesis by A3; end; hence thesis; end; consider k3 being Function such that A4: (a 'or' (a '&' b))=k3 & dom k3=Y & rng k3 c= BOOLEAN by FUNCT_2:def 2; consider k4 being Function such that A5: a=k4 & dom k4=Y & rng k4 c= BOOLEAN by FUNCT_2:def 2; for u being set st u in Y holds k3.u=k4.u by A1,A4,A5; hence thesis by A4,A5,FUNCT_1:9; end; theorem for a,b being Element of Funcs(Y,BOOLEAN) holds a '&' (a 'or' b) = a proof let a,b be Element of Funcs(Y,BOOLEAN); A1:for x being Element of Y holds Pj(a '&' (a 'or' b),x) = Pj(a,x) proof let x be Element of Y; A2:Pj(a '&' (a 'or' b),x) =Pj(a,x) '&' Pj(a 'or' b,x) by VALUAT_1:def 6 .=Pj(a,x) '&' (Pj(a,x) 'or' Pj(b,x)) by BVFUNC_1:def 7; now per cases by MARGREL1:39; case A3:Pj(a,x)=TRUE; then Pj(a '&' (a 'or' b),x) =TRUE '&' TRUE by A2,BINARITH:19 .=TRUE by MARGREL1:45; hence thesis by A3; case Pj(a,x)=FALSE; hence thesis by A2,MARGREL1:45; end; hence thesis; end; consider k3 being Function such that A4: (a '&' (a 'or' b))=k3 & dom k3=Y & rng k3 c= BOOLEAN by FUNCT_2:def 2; consider k4 being Function such that A5: a=k4 & dom k4=Y & rng k4 c= BOOLEAN by FUNCT_2:def 2; for u being set st u in Y holds k3.u=k4.u by A1,A4,A5; hence thesis by A4,A5,FUNCT_1:9; end; theorem Th5: for a being Element of Funcs(Y,BOOLEAN) holds a '&' 'not' a = O_el(Y) proof let a be Element of Funcs(Y,BOOLEAN); A1:for x being Element of Y holds Pj(a '&' 'not' a,x) = Pj(O_el(Y),x) proof let x be Element of Y; A2:Pj(a '&' 'not' a,x) =Pj(a,x) '&' Pj('not' a,x) by VALUAT_1:def 6 .=Pj(a,x) '&' 'not' Pj(a,x) by VALUAT_1:def 5; A3:'not' FALSE=TRUE & 'not' TRUE=FALSE by MARGREL1:41; A4:Pj(O_el(Y),x)=FALSE by BVFUNC_1:def 13; now per cases by MARGREL1:39; case Pj(a,x)=TRUE; hence thesis by A2,A3,A4,MARGREL1:45; case Pj(a,x)=FALSE; hence thesis by A2,A4,MARGREL1:45; end; hence thesis; end; consider k3 being Function such that A5: (a '&' 'not' a)=k3 & dom k3=Y & rng k3 c= BOOLEAN by FUNCT_2:def 2; consider k4 being Function such that A6: O_el(Y)=k4 & dom k4=Y & rng k4 c= BOOLEAN by FUNCT_2:def 2; for u being set st u in Y holds k3.u=k4.u by A1,A5,A6; hence (a '&' 'not' a)=O_el(Y) by A5,A6,FUNCT_1:9; end; theorem for a being Element of Funcs(Y,BOOLEAN) holds a 'or' 'not' a = I_el(Y) proof let a be Element of Funcs(Y,BOOLEAN); A1:for x being Element of Y holds Pj(a 'or' 'not' a,x) = Pj(I_el(Y),x) proof let x be Element of Y; Pj(a 'or' 'not' a,x) =Pj(a,x) 'or' Pj('not' a,x) by BVFUNC_1:def 7 .=Pj(a,x) 'or' 'not' Pj(a,x) by VALUAT_1:def 5 .=TRUE by BINARITH:18; hence thesis by BVFUNC_1:def 14; end; consider k3 being Function such that A2: (a 'or' 'not' a)=k3 & dom k3=Y & rng k3 c= BOOLEAN by FUNCT_2:def 2; consider k4 being Function such that A3: I_el(Y)=k4 & dom k4=Y & rng k4 c= BOOLEAN by FUNCT_2:def 2; for u being set st u in Y holds k3.u=k4.u by A1,A2,A3; hence (a 'or' 'not' a)=I_el(Y) by A2,A3,FUNCT_1:9; end; theorem Th7: for a,b being Element of Funcs(Y,BOOLEAN) holds a 'eqv' b = (a 'imp' b) '&' (b 'imp' a) proof let a,b be Element of Funcs(Y,BOOLEAN); A1:for x being Element of Y holds Pj(a 'eqv' b,x) = Pj((a 'imp' b) '&' (b 'imp' a),x) proof let x be Element of Y; Pj(a 'eqv' b,x) ='not' (Pj(a,x) 'xor' Pj(b,x)) by BVFUNC_1:def 12 .='not' (('not' Pj(a,x) '&' Pj(b,x)) 'or' (Pj(a,x) '&' 'not' Pj(b,x))) by BINARITH:def 2 .='not' ('not' Pj(a,x) '&' Pj(b,x)) '&' 'not' (Pj(a,x) '&' 'not' Pj(b,x)) by BINARITH:10 .=('not' 'not' Pj(a,x) 'or' 'not' Pj(b,x)) '&' 'not' (Pj(a,x) '&' 'not' Pj(b,x)) by BINARITH:9 .=('not' 'not' Pj(a,x) 'or' 'not' Pj(b,x)) '&' ('not' Pj(a,x) 'or' 'not' 'not' Pj(b,x)) by BINARITH:9 .=(Pj(a,x) 'or' 'not' Pj(b,x)) '&' ('not' Pj(a,x) 'or' 'not' 'not' Pj(b,x)) by MARGREL1:40 .=(Pj(a,x) 'or' 'not' Pj(b,x)) '&' ('not' Pj(a,x) 'or' Pj(b,x)) by MARGREL1:40 .=((Pj(a,x) 'or' 'not' Pj(b,x)) '&' 'not' Pj(a,x)) 'or' ((Pj(a,x) 'or' 'not' Pj(b,x)) '&' Pj(b,x)) by BINARITH:22 .=(('not' Pj(a,x) '&' Pj(a,x)) 'or' ('not' Pj(a,x) '&' 'not' Pj(b,x))) 'or' (Pj(b,x) '&' (Pj(a,x) 'or' 'not' Pj(b,x))) by BINARITH:22 .=(('not' Pj(a,x) '&' Pj(a,x)) 'or' ('not' Pj(a,x) '&' 'not' Pj(b,x))) 'or' ((Pj(b,x) '&' Pj(a,x)) 'or' (Pj(b,x) '&' 'not' Pj(b,x))) by BINARITH:22 .=(FALSE 'or' ('not' Pj(a,x) '&' 'not' Pj(b,x))) 'or' ((Pj(b,x) '&' Pj(a,x)) 'or' (Pj(b,x) '&' 'not' Pj(b,x))) by MARGREL1:46 .=(FALSE 'or' ('not' Pj(a,x) '&' 'not' Pj(b,x))) 'or' ((Pj(b,x) '&' Pj(a,x)) 'or' FALSE) by MARGREL1:46 .=('not' Pj(a,x) '&' 'not' Pj(b,x)) 'or' ((Pj(b,x) '&' Pj(a,x)) 'or' FALSE) by BINARITH:7 .=('not' Pj(a,x) '&' 'not' Pj(b,x)) 'or' (Pj(b,x) '&' Pj(a,x)) by BINARITH:7 .=(('not' Pj(a,x) '&' 'not' Pj(b,x)) 'or' Pj(b,x)) '&' (('not' Pj(a,x) '&' 'not' Pj(b,x)) 'or' Pj(a,x)) by BINARITH:23 .=((Pj(b,x) 'or' 'not' Pj(a,x)) '&' (Pj(b,x) 'or' 'not' Pj(b,x))) '&' (Pj(a,x) 'or' ('not' Pj(a,x) '&' 'not' Pj(b,x))) by BINARITH:23 .=((Pj(b,x) 'or' 'not' Pj(a,x)) '&' (Pj(b,x) 'or' 'not' Pj(b,x))) '&' ((Pj(a,x) 'or' 'not' Pj(a,x)) '&' (Pj(a,x) 'or' 'not' Pj(b,x))) by BINARITH:23 .=((Pj(b,x) 'or' 'not' Pj(a,x)) '&' TRUE) '&' ((Pj(a,x) 'or' 'not' Pj(a,x)) '&' (Pj(a,x) 'or' 'not' Pj(b,x))) by BINARITH:18 .=((Pj(b,x) 'or' 'not' Pj(a,x)) '&' TRUE) '&' (TRUE '&' (Pj(a,x) 'or' 'not' Pj(b,x))) by BINARITH:18 .=(Pj(b,x) 'or' 'not' Pj(a,x)) '&' (TRUE '&' (Pj(a,x) 'or' 'not' Pj(b,x))) by MARGREL1:50 .=(Pj(b,x) 'or' 'not' Pj(a,x)) '&' (Pj(a,x) 'or' 'not' Pj(b,x)) by MARGREL1:50 .=Pj(a 'imp' b,x) '&' ('not' Pj(b,x) 'or' Pj(a,x)) by BVFUNC_1:def 11 .=Pj(a 'imp' b,x) '&' Pj(b 'imp' a,x) by BVFUNC_1:def 11 .=Pj((a 'imp' b) '&' (b 'imp' a),x) by VALUAT_1:def 6; hence thesis; end; consider k3 being Function such that A2: (a 'eqv' b)=k3 & dom k3=Y & rng k3 c= BOOLEAN by FUNCT_2:def 2; consider k4 being Function such that A3: ((a 'imp' b) '&' (b 'imp' a))=k4 & dom k4=Y & rng k4 c= BOOLEAN by FUNCT_2:def 2; for u being set st u in Y holds k3.u=k4.u by A1,A2,A3; hence (a 'eqv' b)=((a 'imp' b) '&' (b 'imp' a)) by A2,A3,FUNCT_1:9; end; theorem Th8: for a,b being Element of Funcs(Y,BOOLEAN) holds a 'imp' b = 'not' a 'or' b proof let a,b be Element of Funcs(Y,BOOLEAN); A1:for x being Element of Y holds Pj(a 'imp' b,x) = Pj('not' a 'or' b,x) proof let x be Element of Y; Pj(a 'imp' b,x) =('not' Pj(a,x)) 'or' Pj(b,x) by BVFUNC_1:def 11 .=Pj('not' a,x) 'or' Pj(b,x) by VALUAT_1:def 5 .=Pj('not' a 'or' b,x) by BVFUNC_1:def 7; hence thesis; end; consider k3 being Function such that A2: (a 'imp' b)=k3 & dom k3=Y & rng k3 c= BOOLEAN by FUNCT_2:def 2; consider k4 being Function such that A3: ('not' a 'or' b)=k4 & dom k4=Y & rng k4 c= BOOLEAN by FUNCT_2:def 2; for u being set st u in Y holds k3.u=k4.u by A1,A2,A3; hence thesis by A2,A3,FUNCT_1:9; end; theorem for a,b being Element of Funcs(Y,BOOLEAN) holds a 'xor' b = ('not' a '&' b) 'or' (a '&' 'not' b) proof let a,b be Element of Funcs(Y,BOOLEAN); A1:for x being Element of Y holds Pj(a 'xor' b,x) = Pj(('not' a '&' b) 'or' (a '&' 'not' b),x) proof let x be Element of Y; Pj(a 'xor' b,x) =Pj(a,x) 'xor' Pj(b,x) by BVFUNC_1:def 8 .=('not' Pj(a,x) '&' Pj(b,x)) 'or' (Pj(a,x) '&' 'not' Pj(b,x)) by BINARITH:def 2 .=(Pj('not' a,x) '&' Pj(b,x)) 'or' (Pj(a,x) '&' 'not' Pj(b,x)) by VALUAT_1:def 5 .=(Pj('not' a,x) '&' Pj(b,x)) 'or' (Pj(a,x) '&' Pj('not' b,x)) by VALUAT_1:def 5 .=(Pj('not' a '&' b,x)) 'or' (Pj(a,x) '&' Pj('not' b,x)) by VALUAT_1:def 6 .=Pj('not' a '&' b,x) 'or' Pj(a '&' 'not' b,x) by VALUAT_1:def 6 .=Pj(('not' a '&' b) 'or' (a '&' 'not' b),x) by BVFUNC_1:def 7; hence thesis; end; consider k3 being Function such that A2: (a 'xor' b)=k3 & dom k3=Y & rng k3 c= BOOLEAN by FUNCT_2:def 2; consider k4 being Function such that A3: (('not' a '&' b) 'or' (a '&' 'not' b))=k4 & dom k4=Y & rng k4 c= BOOLEAN by FUNCT_2:def 2; for u being set st u in Y holds k3.u=k4.u by A1,A2,A3; hence thesis by A2,A3,FUNCT_1:9; end; theorem Th10: for a,b being Element of Funcs(Y,BOOLEAN) holds (a 'eqv' b)=I_el(Y) iff ((a 'imp' b)=I_el(Y) & (b 'imp' a)=I_el(Y)) proof let a,b be Element of Funcs(Y,BOOLEAN); thus (a 'eqv' b)=I_el(Y) implies ((a 'imp' b)=I_el(Y) & (b 'imp' a)=I_el(Y)) proof assume (a 'eqv' b)=I_el(Y); then A1: (a 'imp' b) '&' (b 'imp' a)=I_el(Y) by Th7; A2:for x being Element of Y holds Pj(a 'imp' b,x)=TRUE proof let x be Element of Y; Pj((a 'imp' b) '&' (b 'imp' a),x)=TRUE by A1,BVFUNC_1:def 14; then Pj(a 'imp' b,x) '&' Pj(b 'imp' a,x)=TRUE by VALUAT_1:def 6; hence thesis by MARGREL1:45; end; for x being Element of Y holds Pj(b 'imp' a,x)=TRUE proof let x be Element of Y; Pj((a 'imp' b) '&' (b 'imp' a),x)=TRUE by A1,BVFUNC_1:def 14; then Pj(a 'imp' b,x) '&' Pj(b 'imp' a,x)=TRUE by VALUAT_1:def 6; hence thesis by MARGREL1:45; end; hence thesis by A2,BVFUNC_1:def 14; end; assume A3:(a 'imp' b)=I_el(Y) & (b 'imp' a)=I_el(Y); A4:for x being Element of Y holds Pj((a 'imp' b) '&' (b 'imp' a),x)=TRUE proof let x be Element of Y; A5:Pj(b 'imp' a,x)=TRUE by A3,BVFUNC_1:def 14; Pj((a 'imp' b) '&' (b 'imp' a),x) =Pj(a 'imp' b,x) '&' Pj(b 'imp' a,x) by VALUAT_1:def 6 .=TRUE by A3,A5,MARGREL1:45; hence thesis; end; a 'eqv' b = (a 'imp' b) '&' (b 'imp' a) by Th7; hence thesis by A4,BVFUNC_1:def 14; end; theorem for a,b,c being Element of Funcs(Y,BOOLEAN) holds (a 'eqv' b)=I_el(Y) & (b 'eqv' c)=I_el(Y) implies (a 'eqv' c)=I_el(Y) proof let a,b,c be Element of Funcs(Y,BOOLEAN); assume A1:(a 'eqv' b)=I_el(Y) & (b 'eqv' c)=I_el(Y); then A2:(a 'imp' b)=I_el(Y) & (b 'imp' a)=I_el(Y) by Th10; A3:(b 'imp' c)=I_el(Y) & (c 'imp' b)=I_el(Y) by A1,Th10; for x being Element of Y holds Pj(a 'imp' c,x)=TRUE proof let x be Element of Y; Pj(a 'imp' b,x)=TRUE by A2,BVFUNC_1:def 14; then A4:('not' Pj(a,x)) 'or' Pj(b,x)=TRUE by BVFUNC_1:def 11; A5: ('not' Pj(a,x))=TRUE or ('not' Pj(a,x))=FALSE by MARGREL1:39; Pj(b 'imp' c,x)=TRUE by A3,BVFUNC_1:def 14; then A6:('not' Pj(b,x)) 'or' Pj(c,x)=TRUE by BVFUNC_1:def 11; A7: ('not' Pj(b,x))=TRUE or ('not' Pj(b,x))=FALSE by MARGREL1:39; A8:Pj(a 'imp' c,x)=('not' Pj(a,x)) 'or' Pj(c,x) by BVFUNC_1:def 11; now per cases by A4,A5,A6,A7,BINARITH:7; case ('not' Pj(a,x))=TRUE & ('not' Pj(b,x))=TRUE; hence thesis by A8,BINARITH:19; case ('not' Pj(a,x))=TRUE & Pj(c,x)=TRUE; hence thesis by A8,BINARITH:19; case A9:Pj(b,x)=TRUE & ('not' Pj(b,x))=TRUE; then Pj(b,x)=FALSE by MARGREL1:41; hence thesis by A9,MARGREL1:43; case Pj(b,x)=TRUE & Pj(c,x)=TRUE; hence thesis by A8,BINARITH:19; end; hence thesis; end; then A10:a 'imp' c = I_el(Y) by BVFUNC_1:def 14; for x being Element of Y holds Pj(c 'imp' a,x)=TRUE proof let x be Element of Y; Pj(c 'imp' b,x)=TRUE by A3,BVFUNC_1:def 14; then A11:('not' Pj(c,x)) 'or' Pj(b,x)=TRUE by BVFUNC_1:def 11; A12: ('not' Pj(c,x))=TRUE or ('not' Pj(c,x))=FALSE by MARGREL1:39; Pj(b 'imp' a,x)=TRUE by A2,BVFUNC_1:def 14; then A13:('not' Pj(b,x)) 'or' Pj(a,x)=TRUE by BVFUNC_1:def 11; A14: ('not' Pj(b,x))=TRUE or ('not' Pj(b,x))=FALSE by MARGREL1:39; A15:Pj(c 'imp' a,x)=('not' Pj(c,x)) 'or' Pj(a,x) by BVFUNC_1:def 11; now per cases by A11,A12,A13,A14,BINARITH:7; case ('not' Pj(c,x))=TRUE & ('not' Pj(b,x))=TRUE; hence thesis by A15,BINARITH:19; case ('not' Pj(c,x))=TRUE & Pj(a,x)=TRUE; hence thesis by A15,BINARITH:19; case A16:Pj(b,x)=TRUE & ('not' Pj(b,x))=TRUE; then Pj(b,x)=FALSE by MARGREL1:41; hence thesis by A16,MARGREL1:43; case Pj(b,x)=TRUE & Pj(a,x)=TRUE; hence thesis by A15,BINARITH:19; end; hence thesis; end; then c 'imp' a = I_el(Y) by BVFUNC_1:def 14; hence thesis by A10,Th10; end; theorem for a,b being Element of Funcs(Y,BOOLEAN) holds a 'eqv' b=I_el(Y) implies 'not' a 'eqv' 'not' b=I_el(Y) proof let a,b be Element of Funcs(Y,BOOLEAN); assume (a 'eqv' b)=I_el(Y); then A1:(a 'imp' b)=I_el(Y) & (b 'imp' a)=I_el(Y) by Th10; for a,b being Element of Funcs(Y,BOOLEAN) holds (a 'imp' b)=I_el(Y) iff ('not' b 'imp' 'not' a)=I_el(Y) proof let a,b be Element of Funcs(Y,BOOLEAN); A2:now assume A3:(a 'imp' b)=I_el(Y); for x being Element of Y holds Pj('not' b 'imp' 'not' a,x)=TRUE proof let x be Element of Y; Pj(a 'imp' b,x)=TRUE by A3,BVFUNC_1:def 14; then A4:('not' Pj(a,x)) 'or' Pj(b,x)=TRUE by BVFUNC_1:def 11; A5: ('not' Pj(a,x))=TRUE or ('not' Pj(a,x))=FALSE by MARGREL1:39; now per cases by A4,A5,BINARITH:7; case A6:('not' Pj(a,x))=TRUE; Pj('not' b 'imp' 'not' a,x) =('not' Pj('not' b,x)) 'or' Pj('not' a,x) by BVFUNC_1:def 11 .=('not' Pj('not' b,x)) 'or' TRUE by A6,VALUAT_1:def 5 .=TRUE by BINARITH:19; hence thesis; case A7:Pj(b,x)=TRUE; A8:Pj('not' b,x)='not' Pj(b,x) by VALUAT_1:def 5; Pj('not' b 'imp' 'not' a,x) =('not' Pj('not' b,x)) 'or' Pj('not' a,x) by BVFUNC_1:def 11 .=(Pj(b,x)) 'or' Pj('not' a,x) by A8,MARGREL1:40 .=TRUE by A7,BINARITH:19; hence thesis; end; hence thesis; end; hence 'not' b 'imp' 'not' a=I_el(Y) by BVFUNC_1:def 14; end; now assume A9:('not' b 'imp' 'not' a)=I_el(Y); for x being Element of Y holds Pj(a 'imp' b,x)=TRUE proof let x be Element of Y; Pj('not' b 'imp' 'not' a,x)=TRUE by A9,BVFUNC_1:def 14; then ('not' Pj('not' b,x)) 'or' Pj('not' a,x)=TRUE by BVFUNC_1:def 11; then ('not' 'not' Pj(b,x)) 'or' Pj('not' a,x)=TRUE by VALUAT_1:def 5; then ('not' 'not' Pj(b,x)) 'or' 'not' Pj(a,x)=TRUE by VALUAT_1:def 5; then A10:Pj(b,x) 'or' 'not' Pj(a,x)=TRUE by MARGREL1:40; A11: ('not' Pj(a,x))=TRUE or ('not' Pj(a,x))=FALSE by MARGREL1:39; now per cases by A10,A11,BINARITH:7; case A12:('not' Pj(a,x))=TRUE; Pj(a 'imp' b,x) =('not' Pj(a,x)) 'or' Pj(b,x) by BVFUNC_1:def 11 .=TRUE by A12,BINARITH:19; hence thesis; case A13:Pj(b,x)=TRUE; Pj(a 'imp' b,x) =('not' Pj(a,x)) 'or' Pj(b,x) by BVFUNC_1:def 11 .=TRUE by A13,BINARITH:19; hence thesis; end; hence thesis; end; hence a 'imp' b=I_el(Y) by BVFUNC_1:def 14; end; hence thesis by A2; end; then ('not' a 'imp' 'not' b)=I_el(Y) & ('not' b 'imp' 'not' a)=I_el(Y) by A1 ; hence thesis by Th10; end; theorem for a,b,c,d being Element of Funcs(Y,BOOLEAN) holds (a 'eqv' b)=I_el(Y) & (c 'eqv' d)=I_el(Y) implies ((a '&' c) 'eqv' (b '&' d))=I_el(Y) proof let a,b,c,d be Element of Funcs(Y,BOOLEAN); assume A1:(a 'eqv' b)=I_el(Y) & (c 'eqv' d)=I_el(Y); then A2:(a 'imp' b)=I_el(Y) & (b 'imp' a)=I_el(Y) by Th10; A3:(c 'imp' d)=I_el(Y) & (d 'imp' c)=I_el(Y) by A1,Th10; A4:'not' a 'or' b = I_el(Y) by A2,Th8; A5:'not' b 'or' a = I_el(Y) by A2,Th8; A6:'not' c 'or' d = I_el(Y) by A3,Th8; A7:'not' d 'or' c = I_el(Y) by A3,Th8; (a '&' c) 'eqv' (b '&' d) =((a '&' c) 'imp' (b '&' d)) '&' ((b '&' d) 'imp' (a '&' c)) by Th7 .=('not' (a '&' c) 'or' (b '&' d)) '&' ((b '&' d) 'imp' (a '&' c)) by Th8 .=('not' (a '&' c) 'or' (b '&' d)) '&' ('not' (b '&' d) 'or' (a '&' c)) by Th8 .=(('not' a 'or' 'not' c) 'or' (b '&' d)) '&' ('not' (b '&' d) 'or' (a '&' c)) by BVFUNC_1:17 .=(('not' a 'or' 'not' c) 'or' (b '&' d)) '&' (('not' b 'or' 'not' d) 'or' (a '&' c)) by BVFUNC_1:17 .=((('not' a 'or' 'not' c) 'or' b) '&' (('not' a 'or' 'not' c) 'or' d)) '&' (('not' b 'or' 'not' d) 'or' (a '&' c)) by BVFUNC_1:14 .=((('not' a 'or' 'not' c) 'or' b) '&' (('not' a 'or' 'not' c) 'or' d)) '&' ((('not' b 'or' 'not' d) 'or' a) '&' (('not' b 'or' 'not' d) 'or' c)) by BVFUNC_1:14 .=((('not' a 'or' b) 'or' 'not' c) '&' (('not' a 'or' 'not' c) 'or' d)) '&' ((('not' b 'or' 'not' d) 'or' a) '&' (('not' b 'or' 'not' d) 'or' c)) by BVFUNC_1:11 .=(I_el(Y) '&' (('not' a 'or' 'not' c) 'or' d)) '&' ((('not' b 'or' 'not' d) 'or' a) '&' (('not' b 'or' 'not' d) 'or' c)) by A4,BVFUNC_1:13 .=(('not' a 'or' 'not' c) 'or' d) '&' ((('not' b 'or' 'not' d) 'or' a) '&' (('not' b 'or' 'not' d) 'or' c)) by BVFUNC_1:9 .=('not' a 'or' ('not' c 'or' d)) '&' ((('not' b 'or' 'not' d) 'or' a) '&' (('not' b 'or' 'not' d) 'or' c)) by BVFUNC_1:11 .=I_el(Y) '&' ((('not' b 'or' 'not' d) 'or' a) '&' (('not' b 'or' 'not' d) 'or' c)) by A6,BVFUNC_1:13 .=(('not' b 'or' 'not' d) 'or' a) '&' (('not' b 'or' 'not' d) 'or' c) by BVFUNC_1:9 .=(('not' b 'or' 'not' d) 'or' a) '&' ('not' b 'or' ('not' d 'or' c)) by BVFUNC_1:11 .=(('not' b 'or' 'not' d) 'or' a) '&' I_el(Y) by A7,BVFUNC_1:13 .=('not' b 'or' 'not' d) 'or' a by BVFUNC_1:9 .='not' d 'or' ('not' b 'or' a) by BVFUNC_1:11 .=I_el(Y) by A5,BVFUNC_1:13; hence thesis; end; theorem for a,b,c,d being Element of Funcs(Y,BOOLEAN) holds (a 'eqv' b)=I_el(Y) & (c 'eqv' d)=I_el(Y) implies ((a 'imp' c) 'eqv' (b 'imp' d))=I_el(Y) proof let a,b,c,d be Element of Funcs(Y,BOOLEAN); assume A1:(a 'eqv' b)=I_el(Y) & (c 'eqv' d)=I_el(Y); then A2:(a 'imp' b)=I_el(Y) & (b 'imp' a)=I_el(Y) by Th10; A3:(c 'imp' d)=I_el(Y) & (d 'imp' c)=I_el(Y) by A1,Th10; A4:'not' a 'or' b = I_el(Y) by A2,Th8; A5:'not' b 'or' a = I_el(Y) by A2,Th8; A6:'not' c 'or' d = I_el(Y) by A3,Th8; A7:'not' d 'or' c = I_el(Y) by A3,Th8; (a 'imp' c) 'eqv' (b 'imp' d) =((a 'imp' c) 'imp' (b 'imp' d)) '&' ((b 'imp' d) 'imp' (a 'imp' c)) by Th7 .=('not' (a 'imp' c) 'or' (b 'imp' d)) '&' ((b 'imp' d) 'imp' (a 'imp' c)) by Th8 .=('not' (a 'imp' c) 'or' (b 'imp' d)) '&' ('not' (b 'imp' d) 'or' (a 'imp' c)) by Th8 .=('not' ('not' a 'or' c) 'or' (b 'imp' d)) '&' ('not' (b 'imp' d) 'or' (a 'imp' c)) by Th8 .=('not' ('not' a 'or' c) 'or' ('not' b 'or' d)) '&' ('not' (b 'imp' d) 'or' (a 'imp' c)) by Th8 .=('not' ('not' a 'or' c) 'or' ('not' b 'or' d)) '&' ('not' ('not' b 'or' d) 'or' (a 'imp' c)) by Th8 .=('not' ('not' a 'or' c) 'or' ('not' b 'or' d)) '&' ('not' ('not' b 'or' d) 'or' ('not' a 'or' c)) by Th8 .=(('not' 'not' a '&' 'not' c) 'or' ('not' b 'or' d)) '&' ('not' ('not' b 'or' d) 'or' ('not' a 'or' c)) by BVFUNC_1:16 .=(('not' 'not' a '&' 'not' c) 'or' ('not' b 'or' d)) '&' (('not' 'not' b '&' 'not' d) 'or' ('not' a 'or' c)) by BVFUNC_1:16 .=((a '&' 'not' c) 'or' ('not' b 'or' d)) '&' (('not' 'not' b '&' 'not' d) 'or' ('not' a 'or' c)) by BVFUNC_1:4 .=((a '&' 'not' c) 'or' ('not' b 'or' d)) '&' ((b '&' 'not' d) 'or' ('not' a 'or' c)) by BVFUNC_1:4 .=((a 'or' ('not' b 'or' d)) '&' ('not' c 'or' ('not' b 'or' d))) '&' ((b '&' 'not' d) 'or' ('not' a 'or' c)) by BVFUNC_1:14 .=((a 'or' ('not' b 'or' d)) '&' ('not' c 'or' ('not' b 'or' d))) '&' ((b 'or' ('not' a 'or' c)) '&' ('not' d 'or' ('not' a 'or' c))) by BVFUNC_1:14 .=(((a 'or' 'not' b) 'or' d) '&' ('not' c 'or' ('not' b 'or' d))) '&' ((b 'or' ('not' a 'or' c)) '&' ('not' d 'or' ('not' a 'or' c))) by BVFUNC_1:11 .=(((a 'or' 'not' b) 'or' d) '&' ('not' c 'or' ('not' b 'or' d))) '&' (((b 'or' 'not' a) 'or' c) '&' ('not' d 'or' ('not' a 'or' c))) by BVFUNC_1:11 .=(((a 'or' 'not' b) 'or' d) '&' (('not' c 'or' d) 'or' 'not' b)) '&' (((b 'or' 'not' a) 'or' c) '&' ('not' d 'or' (c 'or' 'not' a))) by BVFUNC_1:11 .=((I_el(Y) 'or' d) '&' (I_el(Y) 'or' 'not' b)) '&' ((I_el(Y) 'or' c) '&' (I_el(Y) 'or' 'not' a)) by A4,A5,A6,A7,BVFUNC_1:11 .=(I_el(Y) '&' (I_el(Y) 'or' 'not' b)) '&' ((I_el(Y) 'or' c) '&' (I_el(Y) 'or' 'not' a)) by BVFUNC_1:13 .=(I_el(Y) '&' I_el(Y)) '&' ((I_el(Y) 'or' c) '&' (I_el(Y) 'or' 'not' a)) by BVFUNC_1:13 .=(I_el(Y) '&' I_el(Y)) '&' (I_el(Y) '&' (I_el(Y) 'or' 'not' a)) by BVFUNC_1:13 .=(I_el(Y) '&' I_el(Y)) '&' (I_el(Y) '&' I_el(Y)) by BVFUNC_1:13 .=I_el(Y) '&' (I_el(Y) '&' I_el(Y)) by BVFUNC_1:9 .=I_el(Y) '&' I_el(Y) by BVFUNC_1:9 .=I_el(Y) by BVFUNC_1:9; hence thesis; end; theorem for a,b,c,d being Element of Funcs(Y,BOOLEAN) holds (a 'eqv' b)=I_el(Y) & (c 'eqv' d)=I_el(Y) implies ((a 'or' c) 'eqv' (b 'or' d))=I_el(Y) proof let a,b,c,d be Element of Funcs(Y,BOOLEAN); assume A1:(a 'eqv' b)=I_el(Y) & (c 'eqv' d)=I_el(Y); then A2:(a 'imp' b)=I_el(Y) & (b 'imp' a)=I_el(Y) by Th10; A3:(c 'imp' d)=I_el(Y) & (d 'imp' c)=I_el(Y) by A1,Th10; A4:'not' a 'or' b = I_el(Y) by A2,Th8; A5:'not' b 'or' a = I_el(Y) by A2,Th8; A6:'not' c 'or' d = I_el(Y) by A3,Th8; A7:'not' d 'or' c = I_el(Y) by A3,Th8; (a 'or' c) 'eqv' (b 'or' d) =((a 'or' c) 'imp' (b 'or' d)) '&' ((b 'or' d) 'imp' (a 'or' c)) by Th7 .=('not' (a 'or' c) 'or' (b 'or' d)) '&' ((b 'or' d) 'imp' (a 'or' c)) by Th8 .=('not' (a 'or' c) 'or' (b 'or' d)) '&' ('not' (b 'or' d) 'or' (a 'or' c)) by Th8 .=(('not' a '&' 'not' c) 'or' (b 'or' d)) '&' ('not' (b 'or' d) 'or' (a 'or' c)) by BVFUNC_1:16 .=(('not' a '&' 'not' c) 'or' (b 'or' d)) '&' (('not' b '&' 'not' d) 'or' (a 'or' c)) by BVFUNC_1:16 .=(('not' a 'or' (b 'or' d)) '&' ('not' c 'or' (b 'or' d))) '&' (('not' b '&' 'not' d) 'or' (a 'or' c)) by BVFUNC_1:14 .=(('not' a 'or' (b 'or' d)) '&' ('not' c 'or' (b 'or' d))) '&' (('not' b 'or' (a 'or' c)) '&' ('not' d 'or' (a 'or' c))) by BVFUNC_1:14 .=((('not' a 'or' b) 'or' d) '&' ('not' c 'or' (b 'or' d))) '&' (('not' b 'or' (a 'or' c)) '&' ('not' d 'or' (a 'or' c))) by BVFUNC_1:11 .=((('not' a 'or' b) 'or' d) '&' ('not' c 'or' (b 'or' d))) '&' ((('not' b 'or' a) 'or' c) '&' ('not' d 'or' (a 'or' c))) by BVFUNC_1:11 .=((('not' a 'or' b) 'or' d) '&' (('not' c 'or' d) 'or' b)) '&' ((('not' b 'or' a) 'or' c) '&' ('not' d 'or' (c 'or' a))) by BVFUNC_1:11 .=((I_el(Y) 'or' d) '&' (I_el(Y) 'or' b)) '&' ((I_el(Y) 'or' c) '&' (I_el(Y) 'or' a)) by A4,A5,A6,A7,BVFUNC_1:11 .=(I_el(Y) '&' (I_el(Y) 'or' b)) '&' ((I_el(Y) 'or' c) '&' (I_el(Y) 'or' a)) by BVFUNC_1:13 .=(I_el(Y) '&' I_el(Y)) '&' ((I_el(Y) 'or' c) '&' (I_el(Y) 'or' a)) by BVFUNC_1:13 .=(I_el(Y) '&' I_el(Y)) '&' (I_el(Y) '&' (I_el(Y) 'or' a)) by BVFUNC_1:13 .=(I_el(Y) '&' I_el(Y)) '&' (I_el(Y) '&' I_el(Y)) by BVFUNC_1:13 .=I_el(Y) '&' (I_el(Y) '&' I_el(Y)) by BVFUNC_1:9 .=I_el(Y) '&' I_el(Y) by BVFUNC_1:9 .=I_el(Y) by BVFUNC_1:9; hence thesis; end; theorem for a,b,c,d being Element of Funcs(Y,BOOLEAN) holds (a 'eqv' b)=I_el(Y) & (c 'eqv' d)=I_el(Y) implies ((a 'eqv' c) 'eqv' (b 'eqv' d))=I_el(Y) proof let a,b,c,d be Element of Funcs(Y,BOOLEAN); assume A1:(a 'eqv' b)=I_el(Y) & (c 'eqv' d)=I_el(Y); then A2:(a 'imp' b)=I_el(Y) & (b 'imp' a)=I_el(Y) by Th10; A3:(c 'imp' d)=I_el(Y) & (d 'imp' c)=I_el(Y) by A1,Th10; A4:'not' a 'or' b = I_el(Y) by A2,Th8; A5:'not' b 'or' a = I_el(Y) by A2,Th8; A6:'not' c 'or' d = I_el(Y) by A3,Th8; A7:'not' d 'or' c = I_el(Y) by A3,Th8; A8:(a 'eqv' c) 'eqv' (b 'eqv' d) =(((b 'or' (a 'or' ('not' d 'or' c))) '&' ((a 'or' ('not' d 'or' b)) 'or' 'not' a)) '&' ((b 'or' ('not' c 'or' ('not' d 'or' c))) '&' (('not' c 'or' ('not' d 'or' b)) 'or' 'not' a))) '&' (((a 'or' (b 'or' ('not' c 'or' d))) '&' ((b 'or' ('not' c 'or' a)) 'or' 'not' b)) '&' ((a 'or' (('not' d 'or' 'not' c) 'or' d)) '&' (('not' d 'or' ('not' c 'or' a)) 'or' 'not' b))) proof (a 'eqv' c) 'eqv' (b 'eqv' d) =((a 'eqv' c) 'imp' (b 'eqv' d)) '&' ((b 'eqv' d) 'imp' (a 'eqv' c)) by Th7 .=('not' (a 'eqv' c) 'or' (b 'eqv' d)) '&' ((b 'eqv' d) 'imp' (a 'eqv' c)) by Th8 .=('not' (a 'eqv' c) 'or' (b 'eqv' d)) '&' ('not' (b 'eqv' d) 'or' (a 'eqv' c)) by Th8 .=('not' ((a 'imp' c) '&' (c 'imp' a)) 'or' (b 'eqv' d)) '&' ('not' (b 'eqv' d) 'or' (a 'eqv' c)) by Th7 .=('not' ((a 'imp' c) '&' (c 'imp' a)) 'or' ((b 'imp' d) '&' (d 'imp' b))) '&' ('not' (b 'eqv' d) 'or' (a 'eqv' c)) by Th7 .=('not' ((a 'imp' c) '&' (c 'imp' a)) 'or' ((b 'imp' d) '&' (d 'imp' b))) '&' ('not' ((b 'imp' d) '&' (d 'imp' b)) 'or' (a 'eqv' c)) by Th7 .=('not' ((a 'imp' c) '&' (c 'imp' a)) 'or' ((b 'imp' d) '&' (d 'imp' b))) '&' ('not' ((b 'imp' d) '&' (d 'imp' b)) 'or' ((a 'imp' c) '&' (c 'imp' a))) by Th7 .=('not' (('not' a 'or' c) '&' (c 'imp' a)) 'or' ((b 'imp' d) '&' (d 'imp' b))) '&' ('not' ((b 'imp' d) '&' (d 'imp' b)) 'or' ((a 'imp' c) '&' (c 'imp' a))) by Th8 .=('not' (('not' a 'or' c) '&' ('not' c 'or' a)) 'or' ((b 'imp' d) '&' (d 'imp' b))) '&' ('not' ((b 'imp' d) '&' (d 'imp' b)) 'or' ((a 'imp' c) '&' (c 'imp' a))) by Th8 .=('not' (('not' a 'or' c) '&' ('not' c 'or' a)) 'or' (('not' b 'or' d) '&' (d 'imp' b))) '&' ('not' ((b 'imp' d) '&' (d 'imp' b)) 'or' ((a 'imp' c) '&' (c 'imp' a))) by Th8 .=('not' (('not' a 'or' c) '&' ('not' c 'or' a)) 'or' (('not' b 'or' d) '&' ( 'not' d 'or' b))) '&' ('not' ((b 'imp' d) '&' (d 'imp' b)) 'or' ((a 'imp' c) '&' (c 'imp' a))) by Th8 .=('not' (('not' a 'or' c) '&' ('not' c 'or' a)) 'or' (('not' b 'or' d) '&' ( 'not' d 'or' b))) '&' ('not' (('not' b 'or' d) '&' (d 'imp' b)) 'or' ((a 'imp' c) '&' (c 'imp' a))) by Th8 .=('not' (('not' a 'or' c) '&' ('not' c 'or' a)) 'or' (('not' b 'or' d) '&' ( 'not' d 'or' b))) '&' ('not' (('not' b 'or' d) '&' ('not' d 'or' b)) 'or' ((a 'imp' c) '&' (c 'imp' a))) by Th8 .=('not' (('not' a 'or' c) '&' ('not' c 'or' a)) 'or' (('not' b 'or' d) '&' ( 'not' d 'or' b))) '&' ('not' (('not' b 'or' d) '&' ('not' d 'or' b)) 'or' (('not' a 'or' c) '&' (c 'imp' a))) by Th8 .=('not' (('not' a 'or' c) '&' ('not' c 'or' a)) 'or' (('not' b 'or' d) '&' ( 'not' d 'or' b))) '&' ('not' (('not' b 'or' d) '&' ('not' d 'or' b)) 'or' (('not' a 'or' c) '&' ( 'not' c 'or' a))) by Th8 .=(('not' ('not' a 'or' c) 'or' 'not' ('not' c 'or' a)) 'or' (('not' b 'or' d) '&' ('not' d 'or' b))) '&' ('not' (('not' b 'or' d) '&' ('not' d 'or' b)) 'or' (('not' a 'or' c) '&' ( 'not' c 'or' a))) by BVFUNC_1:17 .=(('not' ('not' a 'or' c) 'or' 'not' ('not' c 'or' a)) 'or' (('not' b 'or' d) '&' ('not' d 'or' b))) '&' (('not' ('not' b 'or' d) 'or' 'not' ('not' d 'or' b)) 'or' (('not' a 'or' c) '&' ('not' c 'or' a))) by BVFUNC_1:17 .=((('not' 'not' a '&' 'not' c) 'or' 'not' ('not' c 'or' a)) 'or' (('not' b 'or' d) '&' ('not' d 'or' b))) '&' (('not' ('not' b 'or' d) 'or' 'not' ('not' d 'or' b)) 'or' (('not' a 'or' c) '&' ('not' c 'or' a))) by BVFUNC_1:16 .=((('not' 'not' a '&' 'not' c) 'or' ('not' 'not' c '&' 'not' a)) 'or' (('not' b 'or' d) '&' ('not' d 'or' b))) '&' (('not' ('not' b 'or' d) 'or' 'not' ('not' d 'or' b)) 'or' (('not' a 'or' c) '&' ('not' c 'or' a))) by BVFUNC_1:16 .=((('not' 'not' a '&' 'not' c) 'or' ('not' 'not' c '&' 'not' a)) 'or' (('not' b 'or' d) '&' ('not' d 'or' b))) '&' ((('not' 'not' b '&' 'not' d) 'or' 'not' ('not' d 'or' b)) 'or' (('not' a 'or' c) '&' ('not' c 'or' a))) by BVFUNC_1:16 .=((('not' 'not' a '&' 'not' c) 'or' ('not' 'not' c '&' 'not' a)) 'or' (('not' b 'or' d) '&' ('not' d 'or' b))) '&' ((('not' 'not' b '&' 'not' d) 'or' ('not' 'not' d '&' 'not' b)) 'or' (('not' a 'or' c) '&' ('not' c 'or' a))) by BVFUNC_1:16 .=(((a '&' 'not' c) 'or' ('not' 'not' c '&' 'not' a)) 'or' (('not' b 'or' d) '&' ('not' d 'or' b))) '&' ((('not' 'not' b '&' 'not' d) 'or' ('not' 'not' d '&' 'not' b)) 'or' (('not' a 'or' c) '&' ('not' c 'or' a))) by BVFUNC_1:4 .=(((a '&' 'not' c) 'or' (c '&' 'not' a)) 'or' (('not' b 'or' d) '&' ('not' d 'or' b))) '&' ((('not' 'not' b '&' 'not' d) 'or' ('not' 'not' d '&' 'not' b)) 'or' (('not' a 'or' c) '&' ('not' c 'or' a))) by BVFUNC_1:4 .=(((a '&' 'not' c) 'or' (c '&' 'not' a)) 'or' (('not' b 'or' d) '&' ('not' d 'or' b))) '&' (((b '&' 'not' d) 'or' ('not' 'not' d '&' 'not' b)) 'or' (('not' a 'or' c) '&' ('not' c 'or' a))) by BVFUNC_1:4 .=(((a '&' 'not' c) 'or' (c '&' 'not' a)) 'or' (('not' b 'or' d) '&' ('not' d 'or' b))) '&' (((b '&' 'not' d) 'or' (d '&' 'not' b)) 'or' (('not' a 'or' c) '&' ('not' c 'or' a))) by BVFUNC_1:4 .=((((a '&' 'not' c) 'or' (c '&' 'not' a)) 'or' ('not' b 'or' d)) '&' (((a '&' 'not' c) 'or' (c '&' 'not' a)) 'or' ('not' d 'or' b))) '&' (((b '&' 'not' d) 'or' (d '&' 'not' b)) 'or' (('not' a 'or' c) '&' ('not' c 'or' a))) by BVFUNC_1:14 .=((((a '&' 'not' c) 'or' (c '&' 'not' a)) 'or' ('not' b 'or' d)) '&' (((a '&' 'not' c) 'or' (c '&' 'not' a)) 'or' ('not' d 'or' b))) '&' ((((b '&' 'not' d) 'or' (d '&' 'not' b)) 'or' ('not' a 'or' c)) '&' (((b '&' 'not' d) 'or' (d '&' 'not' b)) 'or' ('not' c 'or' a))) by BVFUNC_1:14 .=(((a '&' 'not' c) 'or' ((c '&' 'not' a) 'or' ('not' b 'or' d))) '&' (((a '&' 'not' c) 'or' (c '&' 'not' a)) 'or' ('not' d 'or' b))) '&' ((((b '&' 'not' d) 'or' (d '&' 'not' b)) 'or' ('not' a 'or' c)) '&' (((b '&' 'not' d) 'or' (d '&' 'not' b)) 'or' ('not' c 'or' a))) by BVFUNC_1:11 .=(((a '&' 'not' c) 'or' ((c '&' 'not' a) 'or' ('not' b 'or' d))) '&' ((a '&' 'not' c) 'or' ((c '&' 'not' a) 'or' ('not' d 'or' b)))) '&' ((((b '&' 'not' d) 'or' (d '&' 'not' b)) 'or' ('not' a 'or' c)) '&' (((b '&' 'not' d) 'or' (d '&' 'not' b)) 'or' ('not' c 'or' a))) by BVFUNC_1:11 .=(((a '&' 'not' c) 'or' ((c '&' 'not' a) 'or' ('not' b 'or' d))) '&' ((a '&' 'not' c) 'or' ((c '&' 'not' a) 'or' ('not' d 'or' b)))) '&' (((b '&' 'not' d) 'or' ((d '&' 'not' b) 'or' ('not' a 'or' c))) '&' (((b '&' 'not' d) 'or' (d '&' 'not' b)) 'or' ('not' c 'or' a))) by BVFUNC_1:11 .=(((a '&' 'not' c) 'or' ((c '&' 'not' a) 'or' ('not' b 'or' d))) '&' ((a '&' 'not' c) 'or' ((c '&' 'not' a) 'or' ('not' d 'or' b)))) '&' (((b '&' 'not' d) 'or' ((d '&' 'not' b) 'or' ('not' a 'or' c))) '&' ((b '&' 'not' d) 'or' ((d '&' 'not' b) 'or' ('not' c 'or' a)))) by BVFUNC_1:11 .=((((a '&' 'not' c) 'or' ('not' b 'or' d)) 'or' (c '&' 'not' a)) '&' ((a '&' 'not' c) 'or' (('not' d 'or' b) 'or' (c '&' 'not' a)))) '&' (((b '&' 'not' d) 'or' (('not' a 'or' c) 'or' (d '&' 'not' b))) '&' ((b '&' 'not' d) 'or' (('not' c 'or' a) 'or' (d '&' 'not' b)))) by BVFUNC_1:11 .=((((a '&' 'not' c) 'or' ('not' b 'or' d)) 'or' (c '&' 'not' a)) '&' (((a '&' 'not' c) 'or' ('not' d 'or' b)) 'or' (c '&' 'not' a))) '&' (((b '&' 'not' d) 'or' (('not' a 'or' c) 'or' (d '&' 'not' b))) '&' ((b '&' 'not' d) 'or' (('not' c 'or' a) 'or' (d '&' 'not' b)))) by BVFUNC_1:11 .=((((a '&' 'not' c) 'or' ('not' b 'or' d)) 'or' (c '&' 'not' a)) '&' (((a '&' 'not' c) 'or' ('not' d 'or' b)) 'or' (c '&' 'not' a))) '&' ((((b '&' 'not' d) 'or' ('not' a 'or' c)) 'or' (d '&' 'not' b)) '&' ((b '&' 'not' d) 'or' (('not' c 'or' a) 'or' (d '&' 'not' b)))) by BVFUNC_1:11 .=((((a '&' 'not' c) 'or' ('not' b 'or' d)) 'or' (c '&' 'not' a)) '&' (((a '&' 'not' c) 'or' ('not' d 'or' b)) 'or' (c '&' 'not' a))) '&' ((((b '&' 'not' d) 'or' ('not' a 'or' c)) 'or' (d '&' 'not' b)) '&' (((b '&' 'not' d) 'or' ('not' c 'or' a)) 'or' (d '&' 'not' b))) by BVFUNC_1:11 .=((((a 'or' ('not' b 'or' d)) '&' ('not' c 'or' ('not' b 'or' d))) 'or' (c '&' 'not' a)) '&' (((a '&' 'not' c) 'or' ('not' d 'or' b)) 'or' (c '&' 'not' a))) '&' ((((b '&' 'not' d) 'or' ('not' a 'or' c)) 'or' (d '&' 'not' b)) '&' (((b '&' 'not' d) 'or' ('not' c 'or' a)) 'or' (d '&' 'not' b))) by BVFUNC_1:14 .=((((a 'or' ('not' b 'or' d)) '&' ('not' c 'or' ('not' b 'or' d))) 'or' (c '&' 'not' a)) '&' (((a 'or' ('not' d 'or' b)) '&' ('not' c 'or' ('not' d 'or' b))) 'or' (c '&' 'not' a))) '&' ((((b '&' 'not' d) 'or' ('not' a 'or' c)) 'or' (d '&' 'not' b)) '&' (((b '&' 'not' d) 'or' ('not' c 'or' a)) 'or' (d '&' 'not' b))) by BVFUNC_1:14 .=((((a 'or' ('not' b 'or' d)) '&' ('not' c 'or' ('not' b 'or' d))) 'or' (c '&' 'not' a)) '&' (((a 'or' ('not' d 'or' b)) '&' ('not' c 'or' ('not' d 'or' b))) 'or' (c '&' 'not' a))) '&' ((((b 'or' ('not' a 'or' c)) '&' ('not' d 'or' ('not' a 'or' c))) 'or' (d '&' 'not' b)) '&' (((b '&' 'not' d) 'or' ('not' c 'or' a)) 'or' (d '&' 'not' b))) by BVFUNC_1:14 .=((((a 'or' ('not' b 'or' d)) '&' ('not' c 'or' ('not' b 'or' d))) 'or' (c '&' 'not' a)) '&' (((a 'or' ('not' d 'or' b)) '&' ('not' c 'or' ('not' d 'or' b))) 'or' (c '&' 'not' a))) '&' ((((b 'or' ('not' a 'or' c)) '&' ('not' d 'or' ('not' a 'or' c))) 'or' (d '&' 'not' b)) '&' (((b 'or' ('not' c 'or' a)) '&' ('not' d 'or' ('not' c 'or' a))) 'or' (d '&' 'not' b))) by BVFUNC_1:14 .=(((((a 'or' 'not' b) 'or' d) '&' ('not' c 'or' ('not' b 'or' d))) 'or' (c '&' 'not' a)) '&' (((a 'or' ('not' d 'or' b)) '&' ('not' c 'or' ('not' d 'or' b))) 'or' (c '&' 'not' a))) '&' ((((b 'or' ('not' a 'or' c)) '&' ('not' d 'or' ('not' a 'or' c))) 'or' (d '&' 'not' b)) '&' (((b 'or' ('not' c 'or' a)) '&' ('not' d 'or' ('not' c 'or' a))) 'or' (d '&' 'not' b))) by BVFUNC_1:11 .=(((((a 'or' 'not' b) 'or' d) '&' ('not' c 'or' ('not' b 'or' d))) 'or' (c '&' 'not' a)) '&' (((a 'or' ('not' d 'or' b)) '&' ('not' c 'or' ('not' d 'or' b))) 'or' (c '&' 'not' a))) '&' (((((b 'or' 'not' a) 'or' c) '&' ('not' d 'or' ('not' a 'or' c))) 'or' (d '&' 'not' b)) '&' (((b 'or' ('not' c 'or' a)) '&' ('not' d 'or' ('not' c 'or' a))) 'or' (d '&' 'not' b))) by BVFUNC_1:11 .=(((((a 'or' 'not' b) 'or' d) '&' (('not' c 'or' d) 'or' 'not' b)) 'or' (c '&' 'not' a)) '&' (((a 'or' ('not' d 'or' b)) '&' ('not' c 'or' ('not' d 'or' b))) 'or' (c '&' 'not' a))) '&' (((((b 'or' 'not' a) 'or' c) '&' ('not' d 'or' ('not' a 'or' c))) 'or' (d '&' 'not' b)) '&' (((b 'or' ('not' c 'or' a)) '&' ('not' d 'or' ('not' c 'or' a))) 'or' (d '&' 'not' b))) by BVFUNC_1:11 .=((((I_el(Y) 'or' d) '&' (I_el(Y) 'or' 'not' b)) 'or' (c '&' 'not' a)) '&' (((a 'or' ('not' d 'or' b)) '&' ('not' c 'or' ('not' d 'or' b))) 'or' (c '&' 'not' a))) '&' ((((I_el(Y) 'or' c) '&' (I_el(Y) 'or' 'not' a)) 'or' (d '&' 'not' b)) '&' (((b 'or' ('not' c 'or' a)) '&' ('not' d 'or' ('not' c 'or' a))) 'or' (d '&' 'not' b))) by A4,A5,A6,A7,BVFUNC_1:11 .=(((I_el(Y) '&' (I_el(Y) 'or' 'not' b)) 'or' (c '&' 'not' a)) '&' (((a 'or' ('not' d 'or' b)) '&' ('not' c 'or' ('not' d 'or' b))) 'or' (c '&' 'not' a))) '&' ((((I_el(Y) 'or' c) '&' (I_el(Y) 'or' 'not' a)) 'or' (d '&' 'not' b)) '&' (((b 'or' ('not' c 'or' a)) '&' ('not' d 'or' ('not' c 'or' a))) 'or' (d '&' 'not' b))) by BVFUNC_1:13 .=(((I_el(Y) '&' I_el(Y)) 'or' (c '&' 'not' a)) '&' (((a 'or' ('not' d 'or' b)) '&' ('not' c 'or' ('not' d 'or' b))) 'or' (c '&' 'not' a))) '&' ((((I_el(Y) 'or' c) '&' (I_el(Y) 'or' 'not' a)) 'or' (d '&' 'not' b)) '&' (((b 'or' ('not' c 'or' a)) '&' ('not' d 'or' ('not' c 'or' a))) 'or' (d '&' 'not' b))) by BVFUNC_1:13 .=(((I_el(Y) '&' I_el(Y)) 'or' (c '&' 'not' a)) '&' (((a 'or' ('not' d 'or' b)) '&' ('not' c 'or' ('not' d 'or' b))) 'or' (c '&' 'not' a))) '&' (((I_el(Y) '&' (I_el(Y) 'or' 'not' a)) 'or' (d '&' 'not' b)) '&' (((b 'or' ('not' c 'or' a)) '&' ('not' d 'or' ('not' c 'or' a))) 'or' (d '&' 'not' b))) by BVFUNC_1:13 .=(((I_el(Y) '&' I_el(Y)) 'or' (c '&' 'not' a)) '&' (((a 'or' ('not' d 'or' b)) '&' ('not' c 'or' ('not' d 'or' b))) 'or' (c '&' 'not' a))) '&' (((I_el(Y) '&' I_el(Y)) 'or' (d '&' 'not' b)) '&' (((b 'or' ('not' c 'or' a)) '&' ('not' d 'or' ('not' c 'or' a))) 'or' (d '&' 'not' b))) by BVFUNC_1:13 .=((I_el(Y) 'or' (c '&' 'not' a)) '&' (((a 'or' ('not' d 'or' b)) '&' ('not' c 'or' ('not' d 'or' b))) 'or' (c '&' 'not' a))) '&' (((I_el(Y) '&' I_el(Y)) 'or' (d '&' 'not' b)) '&' (((b 'or' ('not' c 'or' a)) '&' ('not' d 'or' ('not' c 'or' a))) 'or' (d '&' 'not' b))) by BVFUNC_1:9 .=((I_el(Y) 'or' (c '&' 'not' a)) '&' (((a 'or' ('not' d 'or' b)) '&' ('not' c 'or' ('not' d 'or' b))) 'or' (c '&' 'not' a))) '&' ((I_el(Y) 'or' (d '&' 'not' b)) '&' (((b 'or' ('not' c 'or' a)) '&' ('not' d 'or' ('not' c 'or' a))) 'or' (d '&' 'not' b))) by BVFUNC_1:9 .=(I_el(Y) '&' (((a 'or' ('not' d 'or' b)) '&' ('not' c 'or' ('not' d 'or' b))) 'or' (c '&' 'not' a))) '&' ((I_el(Y) 'or' (d '&' 'not' b)) '&' (((b 'or' ('not' c 'or' a)) '&' ('not' d 'or' ('not' c 'or' a))) 'or' (d '&' 'not' b))) by BVFUNC_1:13 .=(I_el(Y) '&' (((a 'or' ('not' d 'or' b)) '&' ('not' c 'or' ('not' d 'or' b))) 'or' (c '&' 'not' a))) '&' (I_el(Y) '&' (((b 'or' ('not' c 'or' a)) '&' ('not' d 'or' ('not' c 'or' a))) 'or' (d '&' 'not' b))) by BVFUNC_1:13 .=(((a 'or' ('not' d 'or' b)) '&' ('not' c 'or' ('not' d 'or' b))) 'or' (c '&' 'not' a)) '&' (I_el(Y) '&' (((b 'or' ('not' c 'or' a)) '&' ('not' d 'or' ('not' c 'or' a))) 'or' (d '&' 'not' b))) by BVFUNC_1:9 .=(((a 'or' ('not' d 'or' b)) '&' ('not' c 'or' ('not' d 'or' b))) 'or' (c '&' 'not' a)) '&' (((b 'or' ('not' c 'or' a)) '&' ('not' d 'or' ('not' c 'or' a))) 'or' (d '&' 'not' b)) by BVFUNC_1:9 .=(((a 'or' ('not' d 'or' b)) 'or' (c '&' 'not' a)) '&' (('not' c 'or' ('not' d 'or' b)) 'or' (c '&' 'not' a))) '&' (((b 'or' ('not' c 'or' a)) '&' ('not' d 'or' ('not' c 'or' a))) 'or' (d '&' 'not' b)) by BVFUNC_1:14 .=(((a 'or' ('not' d 'or' b)) 'or' (c '&' 'not' a)) '&' (('not' c 'or' ('not' d 'or' b)) 'or' (c '&' 'not' a))) '&' (((b 'or' ('not' c 'or' a)) 'or' (d '&' 'not' b)) '&' (('not' d 'or' ('not' c 'or' a)) 'or' (d '&' 'not' b))) by BVFUNC_1:14 .=((((a 'or' ('not' d 'or' b)) 'or' c) '&' ((a 'or' ('not' d 'or' b)) 'or' 'not' a)) '&' (('not' c 'or' ('not' d 'or' b)) 'or' (c '&' 'not' a))) '&' (((b 'or' ('not' c 'or' a)) 'or' (d '&' 'not' b)) '&' (('not' d 'or' ('not' c 'or' a)) 'or' (d '&' 'not' b))) by BVFUNC_1:14 .=((((a 'or' ('not' d 'or' b)) 'or' c) '&' ((a 'or' ('not' d 'or' b)) 'or' 'not' a)) '&' ((('not' c 'or' ('not' d 'or' b)) 'or' c) '&' (('not' c 'or' ('not' d 'or' b)) 'or' 'not' a))) '&' (((b 'or' ('not' c 'or' a)) 'or' (d '&' 'not' b)) '&' (('not' d 'or' ('not' c 'or' a)) 'or' (d '&' 'not' b))) by BVFUNC_1:14 .=((((a 'or' ('not' d 'or' b)) 'or' c) '&' ((a 'or' ('not' d 'or' b)) 'or' 'not' a)) '&' ((('not' c 'or' ('not' d 'or' b)) 'or' c) '&' (('not' c 'or' ('not' d 'or' b)) 'or' 'not' a))) '&' ((((b 'or' ('not' c 'or' a)) 'or' d) '&' ((b 'or' ('not' c 'or' a)) 'or' 'not' b)) '&' (('not' d 'or' ('not' c 'or' a)) 'or' (d '&' 'not' b))) by BVFUNC_1:14 .=((((a 'or' ('not' d 'or' b)) 'or' c) '&' ((a 'or' ('not' d 'or' b)) 'or' 'not' a)) '&' ((('not' c 'or' ('not' d 'or' b)) 'or' c) '&' (('not' c 'or' ('not' d 'or' b)) 'or' 'not' a))) '&' ((((b 'or' ('not' c 'or' a)) 'or' d) '&' ((b 'or' ('not' c 'or' a)) 'or' 'not' b)) '&' ((('not' d 'or' ('not' c 'or' a)) 'or' d) '&' (('not' d 'or' ('not' c 'or' a)) 'or' 'not' b))) by BVFUNC_1:14 .=(((((a 'or' 'not' d) 'or' b) 'or' c) '&' ((a 'or' ('not' d 'or' b)) 'or' 'not' a)) '&' ((('not' c 'or' ('not' d 'or' b)) 'or' c) '&' (('not' c 'or' ('not' d 'or' b)) 'or' 'not' a))) '&' ((((b 'or' ('not' c 'or' a)) 'or' d) '&' ((b 'or' ('not' c 'or' a)) 'or' 'not' b)) '&' ((('not' d 'or' ('not' c 'or' a)) 'or' d) '&' (('not' d 'or' ('not' c 'or' a)) 'or' 'not' b))) by BVFUNC_1:11 .=(((b 'or' ((a 'or' 'not' d) 'or' c)) '&' ((a 'or' ('not' d 'or' b)) 'or' 'not' a)) '&' ((('not' c 'or' ('not' d 'or' b)) 'or' c) '&' (('not' c 'or' ('not' d 'or' b)) 'or' 'not' a))) '&' ((((b 'or' ('not' c 'or' a)) 'or' d) '&' ((b 'or' ('not' c 'or' a)) 'or' 'not' b)) '&' ((('not' d 'or' ('not' c 'or' a)) 'or' d) '&' (('not' d 'or' ('not' c 'or' a)) 'or' 'not' b))) by BVFUNC_1:11 .=(((b 'or' (a 'or' ('not' d 'or' c))) '&' ((a 'or' ('not' d 'or' b)) 'or' 'not' a)) '&' ((('not' c 'or' ('not' d 'or' b)) 'or' c) '&' (('not' c 'or' ('not' d 'or' b)) 'or' 'not' a))) '&' ((((b 'or' ('not' c 'or' a)) 'or' d) '&' ((b 'or' ('not' c 'or' a)) 'or' 'not' b)) '&' ((('not' d 'or' ('not' c 'or' a)) 'or' d) '&' (('not' d 'or' ('not' c 'or' a)) 'or' 'not' b))) by BVFUNC_1:11 .=(((b 'or' (a 'or' ('not' d 'or' c))) '&' ((a 'or' ('not' d 'or' b)) 'or' 'not' a)) '&' (((('not' c 'or' 'not' d) 'or' b) 'or' c) '&' (('not' c 'or' ('not' d 'or' b)) 'or' 'not' a))) '&' ((((b 'or' ('not' c 'or' a)) 'or' d) '&' ((b 'or' ('not' c 'or' a)) 'or' 'not' b)) '&' ((('not' d 'or' ('not' c 'or' a)) 'or' d) '&' (('not' d 'or' ('not' c 'or' a)) 'or' 'not' b))) by BVFUNC_1:11 .=(((b 'or' (a 'or' ('not' d 'or' c))) '&' ((a 'or' ('not' d 'or' b)) 'or' 'not' a)) '&' ((b 'or' (('not' c 'or' 'not' d) 'or' c)) '&' (('not' c 'or' ('not' d 'or' b)) 'or' 'not' a))) '&' ((((b 'or' ('not' c 'or' a)) 'or' d) '&' ((b 'or' ('not' c 'or' a)) 'or' 'not' b)) '&' ((('not' d 'or' ('not' c 'or' a)) 'or' d) '&' (('not' d 'or' ('not' c 'or' a)) 'or' 'not' b))) by BVFUNC_1:11 .=(((b 'or' (a 'or' ('not' d 'or' c))) '&' ((a 'or' ('not' d 'or' b)) 'or' 'not' a)) '&' ((b 'or' ('not' c 'or' ('not' d 'or' c))) '&' (('not' c 'or' ('not' d 'or' b)) 'or' 'not' a))) '&' ((((b 'or' ('not' c 'or' a)) 'or' d) '&' ((b 'or' ('not' c 'or' a)) 'or' 'not' b)) '&' ((('not' d 'or' ('not' c 'or' a)) 'or' d) '&' (('not' d 'or' ('not' c 'or' a)) 'or' 'not' b))) by BVFUNC_1:11 .=(((b 'or' (a 'or' ('not' d 'or' c))) '&' ((a 'or' ('not' d 'or' b)) 'or' 'not' a)) '&' ((b 'or' ('not' c 'or' ('not' d 'or' c))) '&' (('not' c 'or' ('not' d 'or' b)) 'or' 'not' a))) '&' (((((b 'or' 'not' c) 'or' a) 'or' d) '&' ((b 'or' ('not' c 'or' a)) 'or' 'not' b)) '&' ((('not' d 'or' ('not' c 'or' a)) 'or' d) '&' (('not' d 'or' ('not' c 'or' a)) 'or' 'not' b))) by BVFUNC_1:11 .=(((b 'or' (a 'or' ('not' d 'or' c))) '&' ((a 'or' ('not' d 'or' b)) 'or' 'not' a)) '&' ((b 'or' ('not' c 'or' ('not' d 'or' c))) '&' (('not' c 'or' ('not' d 'or' b)) 'or' 'not' a))) '&' (((a 'or' ((b 'or' 'not' c) 'or' d)) '&' ((b 'or' ('not' c 'or' a)) 'or' 'not' b)) '&' ((('not' d 'or' ('not' c 'or' a)) 'or' d) '&' (('not' d 'or' ('not' c 'or' a)) 'or' 'not' b))) by BVFUNC_1:11 .=(((b 'or' (a 'or' ('not' d 'or' c))) '&' ((a 'or' ('not' d 'or' b)) 'or' 'not' a)) '&' ((b 'or' ('not' c 'or' ('not' d 'or' c))) '&' (('not' c 'or' ('not' d 'or' b)) 'or' 'not' a))) '&' (((a 'or' (b 'or' ('not' c 'or' d))) '&' ((b 'or' ('not' c 'or' a)) 'or' 'not' b)) '&' ((('not' d 'or' ('not' c 'or' a)) 'or' d) '&' (('not' d 'or' ('not' c 'or' a)) 'or' 'not' b))) by BVFUNC_1:11 .=(((b 'or' (a 'or' ('not' d 'or' c))) '&' ((a 'or' ('not' d 'or' b)) 'or' 'not' a)) '&' ((b 'or' ('not' c 'or' ('not' d 'or' c))) '&' (('not' c 'or' ('not' d 'or' b)) 'or' 'not' a))) '&' (((a 'or' (b 'or' ('not' c 'or' d))) '&' ((b 'or' ('not' c 'or' a)) 'or' 'not' b)) '&' (((('not' d 'or' 'not' c) 'or' a) 'or' d) '&' (('not' d 'or' ('not' c 'or' a)) 'or' 'not' b))) by BVFUNC_1:11 .=(((b 'or' (a 'or' ('not' d 'or' c))) '&' ((a 'or' ('not' d 'or' b)) 'or' 'not' a)) '&' ((b 'or' ('not' c 'or' ('not' d 'or' c))) '&' (('not' c 'or' ('not' d 'or' b)) 'or' 'not' a))) '&' (((a 'or' (b 'or' ('not' c 'or' d))) '&' ((b 'or' ('not' c 'or' a)) 'or' 'not' b)) '&' ((a 'or' (('not' d 'or' 'not' c) 'or' d)) '&' (('not' d 'or' ('not' c 'or' a)) 'or' 'not' b))) by BVFUNC_1:11; hence thesis; end; (((b 'or' (a 'or' ('not' d 'or' c))) '&' ((a 'or' ('not' d 'or' b)) 'or' 'not' a)) '&' ((b 'or' ('not' c 'or' ('not' d 'or' c))) '&' (('not' c 'or' ('not' d 'or' b)) 'or' 'not' a))) '&' (((a 'or' (b 'or' ('not' c 'or' d))) '&' ((b 'or' ('not' c 'or' a)) 'or' 'not' b)) '&' ((a 'or' (('not' d 'or' 'not' c) 'or' d)) '&' (('not' d 'or' ('not' c 'or' a)) 'or' 'not' b))) =(((b 'or' (a 'or' ('not' d 'or' c))) '&' ((a 'or' ('not' d 'or' b)) 'or' 'not' a)) '&' ((b 'or' ('not' c 'or' ('not' d 'or' c))) '&' (('not' c 'or' ('not' d 'or' b)) 'or' 'not' a))) '&' (((a 'or' (b 'or' ('not' c 'or' d))) '&' ((b 'or' ('not' c 'or' a)) 'or' 'not' b)) '&' ((a 'or' ('not' d 'or' ('not' c 'or' d))) '&' (('not' d 'or' ('not' c 'or' a)) 'or' 'not' b))) by BVFUNC_1:11 .=(((b 'or' I_el(Y)) '&' ((a 'or' ('not' d 'or' b)) 'or' 'not' a)) '&' ((b 'or' ('not' c 'or' I_el(Y))) '&' (('not' c 'or' ('not' d 'or' b)) 'or' 'not' a))) '&' (((a 'or' (b 'or' I_el(Y))) '&' ((b 'or' ('not' c 'or' a)) 'or' 'not' b)) '&' ((a 'or' ('not' d 'or' I_el(Y))) '&' (('not' d 'or' ('not' c 'or' a)) 'or' 'not' b))) by A6,A7,BVFUNC_1:13 .=(((b 'or' I_el(Y)) '&' ((a 'or' ('not' d 'or' b)) 'or' 'not' a)) '&' ((b 'or' I_el(Y)) '&' (('not' c 'or' ('not' d 'or' b)) 'or' 'not' a))) '&' (((a 'or' (b 'or' I_el(Y))) '&' ((b 'or' ('not' c 'or' a)) 'or' 'not' b)) '&' ((a 'or' ('not' d 'or' I_el(Y))) '&' (('not' d 'or' ('not' c 'or' a)) 'or' 'not' b))) by BVFUNC_1:13 .=(((b 'or' I_el(Y)) '&' ((a 'or' ('not' d 'or' b)) 'or' 'not' a)) '&' ((b 'or' I_el(Y)) '&' (('not' c 'or' ('not' d 'or' b)) 'or' 'not' a))) '&' (((a 'or' I_el(Y)) '&' ((b 'or' ('not' c 'or' a)) 'or' 'not' b)) '&' ((a 'or' ('not' d 'or' I_el(Y))) '&' (('not' d 'or' ('not' c 'or' a)) 'or' 'not' b))) by BVFUNC_1:13 .=(((b 'or' I_el(Y)) '&' ((a 'or' ('not' d 'or' b)) 'or' 'not' a)) '&' ((b 'or' I_el(Y)) '&' (('not' c 'or' ('not' d 'or' b)) 'or' 'not' a))) '&' (((a 'or' I_el(Y)) '&' ((b 'or' ('not' c 'or' a)) 'or' 'not' b)) '&' ((a 'or' I_el(Y)) '&' (('not' d 'or' ('not' c 'or' a)) 'or' 'not' b))) by BVFUNC_1:13 .=((I_el(Y) '&' ((a 'or' ('not' d 'or' b)) 'or' 'not' a)) '&' ((b 'or' I_el(Y)) '&' (('not' c 'or' ('not' d 'or' b)) 'or' 'not' a))) '&' (((a 'or' I_el(Y)) '&' ((b 'or' ('not' c 'or' a)) 'or' 'not' b)) '&' ((a 'or' I_el(Y)) '&' (('not' d 'or' ('not' c 'or' a)) 'or' 'not' b))) by BVFUNC_1:13 .=((I_el(Y) '&' ((a 'or' ('not' d 'or' b)) 'or' 'not' a)) '&' (I_el(Y) '&' (('not' c 'or' ('not' d 'or' b)) 'or' 'not' a))) '&' (((a 'or' I_el(Y)) '&' ((b 'or' ('not' c 'or' a)) 'or' 'not' b)) '&' ((a 'or' I_el(Y)) '&' (('not' d 'or' ('not' c 'or' a)) 'or' 'not' b))) by BVFUNC_1:13 .=((I_el(Y) '&' ((a 'or' ('not' d 'or' b)) 'or' 'not' a)) '&' (I_el(Y) '&' (('not' c 'or' ('not' d 'or' b)) 'or' 'not' a))) '&' ((I_el(Y) '&' ((b 'or' ('not' c 'or' a)) 'or' 'not' b)) '&' ((a 'or' I_el(Y)) '&' (('not' d 'or' ('not' c 'or' a)) 'or' 'not' b))) by BVFUNC_1:13 .=((I_el(Y) '&' ((a 'or' ('not' d 'or' b)) 'or' 'not' a)) '&' (I_el(Y) '&' (('not' c 'or' ('not' d 'or' b)) 'or' 'not' a))) '&' ((I_el(Y) '&' ((b 'or' ('not' c 'or' a)) 'or' 'not' b)) '&' (I_el(Y) '&' (('not' d 'or' ('not' c 'or' a)) 'or' 'not' b))) by BVFUNC_1:13 .=(((a 'or' ('not' d 'or' b)) 'or' 'not' a) '&' (I_el(Y) '&' (('not' c 'or' ('not' d 'or' b)) 'or' 'not' a))) '&' ((I_el(Y) '&' ((b 'or' ('not' c 'or' a)) 'or' 'not' b)) '&' (I_el(Y) '&' (('not' d 'or' ('not' c 'or' a)) 'or' 'not' b))) by BVFUNC_1:9 .=(((a 'or' ('not' d 'or' b)) 'or' 'not' a) '&' (('not' c 'or' ('not' d 'or' b)) 'or' 'not' a)) '&' ((I_el(Y) '&' ((b 'or' ('not' c 'or' a)) 'or' 'not' b)) '&' (I_el(Y) '&' (('not' d 'or' ('not' c 'or' a)) 'or' 'not' b))) by BVFUNC_1:9 .=(((a 'or' ('not' d 'or' b)) 'or' 'not' a) '&' (('not' c 'or' ('not' d 'or' b)) 'or' 'not' a)) '&' (((b 'or' ('not' c 'or' a)) 'or' 'not' b) '&' (I_el(Y) '&' (('not' d 'or' ('not' c 'or' a)) 'or' 'not' b))) by BVFUNC_1:9 .=(((a 'or' ('not' d 'or' b)) 'or' 'not' a) '&' (('not' c 'or' ('not' d 'or' b)) 'or' 'not' a)) '&' (((b 'or' ('not' c 'or' a)) 'or' 'not' b) '&' (('not' d 'or' ('not' c 'or' a)) 'or' 'not' b)) by BVFUNC_1:9 .=((a 'or' (('not' d 'or' b) 'or' 'not' a)) '&' (('not' c 'or' ('not' d 'or' b)) 'or' 'not' a)) '&' (((b 'or' ('not' c 'or' a)) 'or' 'not' b) '&' (('not' d 'or' ('not' c 'or' a)) 'or' 'not' b)) by BVFUNC_1:11 .=((a 'or' ('not' d 'or' (b 'or' 'not' a))) '&' (('not' c 'or' ('not' d 'or' b)) 'or' 'not' a)) '&' (((b 'or' ('not' c 'or' a)) 'or' 'not' b) '&' (('not' d 'or' ('not' c 'or' a)) 'or' 'not' b)) by BVFUNC_1:11 .=((a 'or' ('not' d 'or' (b 'or' 'not' a))) '&' ('not' c 'or' (('not' d 'or' b) 'or' 'not' a))) '&' (((b 'or' ('not' c 'or' a)) 'or' 'not' b) '&' (('not' d 'or' ('not' c 'or' a)) 'or' 'not' b)) by BVFUNC_1:11 .=((a 'or' ('not' d 'or' (b 'or' 'not' a))) '&' ('not' c 'or' ('not' d 'or' (b 'or' 'not' a)))) '&' (((b 'or' ('not' c 'or' a)) 'or' 'not' b) '&' (('not' d 'or' ('not' c 'or' a)) 'or' 'not' b)) by BVFUNC_1:11 .=((a 'or' ('not' d 'or' (b 'or' 'not' a))) '&' ('not' c 'or' ('not' d 'or' (b 'or' 'not' a)))) '&' ((b 'or' (('not' c 'or' a) 'or' 'not' b)) '&' (('not' d 'or' ('not' c 'or' a)) 'or' 'not' b)) by BVFUNC_1:11 .=((a 'or' ('not' d 'or' (b 'or' 'not' a))) '&' ('not' c 'or' ('not' d 'or' (b 'or' 'not' a)))) '&' ((b 'or' ('not' c 'or' (a 'or' 'not' b))) '&' (('not' d 'or' ('not' c 'or' a)) 'or' 'not' b)) by BVFUNC_1:11 .=((a 'or' ('not' d 'or' (b 'or' 'not' a))) '&' ('not' c 'or' ('not' d 'or' (b 'or' 'not' a)))) '&' ((b 'or' ('not' c 'or' (a 'or' 'not' b))) '&' ('not' d 'or' (('not' c 'or' a) 'or' 'not' b))) by BVFUNC_1:11 .=((a 'or' ('not' d 'or' I_el(Y))) '&' ('not' c 'or' ('not' d 'or' I_el(Y)))) '&' ((b 'or' ('not' c 'or' I_el(Y))) '&' ('not' d 'or' ('not' c 'or' I_el(Y)))) by A4,A5,BVFUNC_1:11 .=((a 'or' I_el(Y)) '&' ('not' c 'or' ('not' d 'or' I_el(Y)))) '&' ((b 'or' ('not' c 'or' I_el(Y))) '&' ('not' d 'or' ('not' c 'or' I_el(Y)))) by BVFUNC_1:13 .=((a 'or' I_el(Y)) '&' ('not' c 'or' I_el(Y))) '&' ((b 'or' ('not' c 'or' I_el(Y))) '&' ('not' d 'or' ('not' c 'or' I_el(Y)))) by BVFUNC_1:13 .=((a 'or' I_el(Y)) '&' ('not' c 'or' I_el(Y))) '&' ((b 'or' I_el(Y)) '&' ('not' d 'or' ('not' c 'or' I_el(Y)))) by BVFUNC_1:13 .=((a 'or' I_el(Y)) '&' ('not' c 'or' I_el(Y))) '&' ((b 'or' I_el(Y)) '&' ('not' d 'or' I_el(Y))) by BVFUNC_1:13 .=(I_el(Y) '&' ('not' c 'or' I_el(Y))) '&' ((b 'or' I_el(Y)) '&' ('not' d 'or' I_el(Y))) by BVFUNC_1:13 .=(I_el(Y) '&' I_el(Y)) '&' ((b 'or' I_el(Y)) '&' ('not' d 'or' I_el(Y))) by BVFUNC_1:13 .=(I_el(Y) '&' I_el(Y)) '&' (I_el(Y) '&' ('not' d 'or' I_el(Y))) by BVFUNC_1:13 .=(I_el(Y) '&' I_el(Y)) '&' (I_el(Y) '&' I_el(Y)) by BVFUNC_1:13 .=I_el(Y) '&' (I_el(Y) '&' I_el(Y)) by BVFUNC_1:9 .=I_el(Y) '&' I_el(Y) by BVFUNC_1:9 .=I_el(Y) by BVFUNC_1:9; hence thesis by A8; end; begin ::Chap. 2 Predicate Calculus theorem for a,b being Element of Funcs(Y,BOOLEAN), G being Subset of PARTITIONS(Y), PA being a_partition of Y holds All(a 'eqv' b,PA,G) = All(a 'imp' b,PA,G) '&' All(b 'imp' a,PA,G) proof let a,b be Element of Funcs(Y,BOOLEAN); let G be Subset of PARTITIONS(Y); let PA be a_partition of Y; A1:for z being Element of Y holds Pj(All(a 'eqv' b,PA,G),z) = Pj(All(a 'imp' b,PA,G) '&' All(b 'imp' a,PA,G),z) proof let z be Element of Y; Pj(All(a 'eqv' b,PA,G),z) =Pj(All((a 'imp' b) '&' (b 'imp' a),PA,G),z) by Th7 .=Pj(All(a 'imp' b,PA,G) '&' All(b 'imp' a,PA,G),z) by BVFUNC_2:13; hence thesis; end; consider k3 being Function such that A2: (All(a 'eqv' b,PA,G))=k3 & dom k3=Y & rng k3 c= BOOLEAN by FUNCT_2:def 2; consider k4 being Function such that A3: (All(a 'imp' b,PA,G) '&' All(b 'imp' a,PA,G))=k4 & dom k4=Y & rng k4 c= BOOLEAN by FUNCT_2:def 2; Y=dom k3 & Y=dom k4 & (for u being set st u in Y holds k3.u=k4.u)by A1,A2,A3; hence (All(a 'eqv' b,PA,G))= (All(a 'imp' b,PA,G) '&' All(b 'imp' a,PA,G)) by A2,A3,FUNCT_1:9; end; theorem for a being Element of Funcs(Y,BOOLEAN), G being Subset of PARTITIONS(Y), PA,PB being a_partition of Y holds All(a,PA,G) '<' Ex(a,PB,G) proof let a be Element of Funcs(Y,BOOLEAN); let G be Subset of PARTITIONS(Y); let PA,PB be a_partition of Y; thus All(a,PA,G) '<' Ex(a,PB,G) proof A1:All(a,PA,G) '<' a by BVFUNC_2:11; a '<' Ex(a,PB,G) by BVFUNC_2:12; hence thesis by A1,BVFUNC_1:18; end; end; theorem for a,u being Element of Funcs(Y,BOOLEAN), G being Subset of PARTITIONS(Y), PA being a_partition of Y st G is independent & PA in G & u is_independent_of PA,G holds a 'imp' u = I_el(Y) implies All(a,PA,G) 'imp' u = I_el(Y) proof let a,u be Element of Funcs(Y,BOOLEAN); let G be Subset of PARTITIONS(Y); let PA be a_partition of Y; assume A1:G is independent & PA in G & u is_independent_of PA,G & a 'imp' u = I_el(Y); A2:All(a,PA,G) = B_INF(a,CompF(PA,G)) by BVFUNC_2:def 9; for x being Element of Y holds Pj(All(a,PA,G) 'imp' u,x) = TRUE proof let x be Element of Y; Pj(a 'imp' u,x) = TRUE by A1,BVFUNC_1:def 14; then A3:'not' Pj(a,x) 'or' Pj(u,x) = TRUE by BVFUNC_1:def 11; A4:'not' Pj(a,x)=TRUE or 'not' Pj(a,x)=FALSE by MARGREL1:39; now per cases by A3,A4,BINARITH:7; case 'not' Pj(a,x)=TRUE; then Pj(a,x)=FALSE by MARGREL1:41; then A5:Pj(a,x)<>TRUE by MARGREL1:43; x in EqClass(x,CompF(PA,G)) & EqClass(x,CompF(PA,G)) in CompF(PA,G) by T_1TOPSP:def 1; then Pj(B_INF(a,CompF(PA,G)),x) = FALSE by A5,BVFUNC_1:def 19; then Pj(All(a,PA,G) 'imp' u,x) ='not' FALSE 'or' Pj(u,x) by A2,BVFUNC_1: def 11 .=TRUE 'or' Pj(u,x) by MARGREL1:41 .=TRUE by BINARITH:19; hence thesis; case Pj(u,x)=TRUE; then Pj(All(a,PA,G) 'imp' u,x) ='not' Pj(All(a,PA,G),x) 'or' TRUE by BVFUNC_1:def 11 .=TRUE by BINARITH:19; hence thesis; end; hence thesis; end; hence All(a,PA,G) 'imp' u = I_el(Y) by BVFUNC_1:def 14; end; theorem for u being Element of Funcs(Y,BOOLEAN), G being Subset of PARTITIONS(Y), PA being a_partition of Y st u is_independent_of PA,G holds Ex(u,PA,G) '<' u proof let u be Element of Funcs(Y,BOOLEAN); let G be Subset of PARTITIONS(Y); let PA be a_partition of Y; assume u is_independent_of PA,G; then A1: u is_dependent_of CompF(PA,G) by BVFUNC_2:def 8; A2:Ex(u,PA,G) = B_SUP(u,CompF(PA,G)) by BVFUNC_2:def 10; for z being Element of Y holds Pj(Ex(u,PA,G) 'imp' u,z) = TRUE proof let z be Element of Y; A3:z in EqClass(z,CompF(PA,G)) & EqClass(z,CompF(PA,G)) in CompF(PA,G) by T_1TOPSP:def 1; A4:Pj(Ex(u,PA,G) 'imp' u,z) ='not' Pj(Ex(u,PA,G),z) 'or' Pj(u,z) by BVFUNC_1:def 11; now per cases by MARGREL1:39; case Pj(u,z)=TRUE; hence thesis by A4,BINARITH:19; case A5:Pj(u,z)=FALSE; now given x1 being Element of Y such that A6:x1 in EqClass(z,CompF(PA,G)) & Pj(u,x1)=TRUE; u.z=u.x1 by A1,A3,A6,BVFUNC_1:def 18; hence contradiction by A5,A6,MARGREL1:43; end; then Pj(B_SUP(u,CompF(PA,G)),z) = FALSE by BVFUNC_1:def 20; then Pj(Ex(u,PA,G) 'imp' u,z) =TRUE 'or' Pj(u,z) by A2,A4,MARGREL1:41 .=TRUE by BINARITH:19; hence thesis; end; hence thesis; end; then Ex(u,PA,G) 'imp' u = I_el(Y) by BVFUNC_1:def 14; hence thesis by BVFUNC_1:19; end; theorem for u being Element of Funcs(Y,BOOLEAN), G being Subset of PARTITIONS(Y), PA being a_partition of Y st u is_independent_of PA,G holds u '<' All(u,PA,G) proof let u be Element of Funcs(Y,BOOLEAN); let G be Subset of PARTITIONS(Y); let PA be a_partition of Y; assume u is_independent_of PA,G; then A1: u is_dependent_of CompF(PA,G) by BVFUNC_2:def 8; A2:All(u,PA,G) = B_INF(u,CompF(PA,G)) by BVFUNC_2:def 9; for z being Element of Y holds Pj(u 'imp' All(u,PA,G),z) = TRUE proof let z be Element of Y; A3:z in EqClass(z,CompF(PA,G)) & EqClass(z,CompF(PA,G)) in CompF(PA,G) by T_1TOPSP:def 1; A4:Pj(u 'imp' All(u,PA,G),z) ='not' Pj(u,z) 'or' Pj(All(u,PA,G),z) by BVFUNC_1:def 11; now per cases by MARGREL1:39; case Pj(u,z)=FALSE; then Pj(u 'imp' All(u,PA,G),z) =TRUE 'or' Pj(All(u,PA,G),z) by A4,MARGREL1:41 .=TRUE by BINARITH:19; hence thesis; case Pj(u,z)=TRUE; then for x being Element of Y st x in EqClass(z,CompF(PA,G)) holds Pj(u,x)=TRUE by A1,A3,BVFUNC_1:def 18; then Pj(All(u,PA,G),z)=TRUE by A2,BVFUNC_1:def 19; hence thesis by A4,BINARITH:19; end; hence thesis; end; then u 'imp' All(u,PA,G) = I_el(Y) by BVFUNC_1:def 14; hence thesis by BVFUNC_1:19; end; theorem for u being Element of Funcs(Y,BOOLEAN), G being Subset of PARTITIONS(Y), PA,PB being a_partition of Y st u is_independent_of PB,G holds All(u,PA,G) '<' All(u,PB,G) proof let u be Element of Funcs(Y,BOOLEAN); let G be Subset of PARTITIONS(Y); let PA,PB be a_partition of Y; assume u is_independent_of PB,G; then A1: u is_dependent_of CompF(PB,G) by BVFUNC_2:def 8; A2:All(u,PA,G) = B_INF(u,CompF(PA,G)) by BVFUNC_2:def 9; A3:All(u,PB,G) = B_INF(u,CompF(PB,G)) by BVFUNC_2:def 9; for z being Element of Y holds Pj(All(u,PA,G) 'imp' All(u,PB,G),z) = TRUE proof let z be Element of Y; A4:z in EqClass(z,CompF(PA,G)) & EqClass(z,CompF(PA,G)) in CompF(PA,G) by T_1TOPSP:def 1; A5:z in EqClass(z,CompF(PB,G)) & EqClass(z,CompF(PB,G)) in CompF(PB,G) by T_1TOPSP:def 1; A6:Pj(All(u,PA,G) 'imp' All(u,PB,G),z) ='not' Pj(All(u,PA,G),z) 'or' Pj(All(u,PB,G),z) by BVFUNC_1:def 11; now per cases by MARGREL1:39; case Pj(All(u,PA,G),z)=FALSE; then Pj(All(u,PA,G) 'imp' All(u,PB,G),z) =TRUE 'or' Pj(All(u,PB,G),z) by A6,MARGREL1:41 .=TRUE by BINARITH:19; hence thesis; case A7:Pj(All(u,PA,G),z)=TRUE; now assume not (for x being Element of Y st x in EqClass(z,CompF(PA,G)) holds Pj(u,x)=TRUE); then Pj(All(u,PA,G),z)=FALSE by A2,BVFUNC_1:def 19; hence contradiction by A7,MARGREL1:43; end; then Pj(u,z)=TRUE by A4; then for x being Element of Y st x in EqClass(z,CompF(PB,G)) holds Pj(u,x)=TRUE by A1,A5,BVFUNC_1:def 18; then Pj(All(u,PB,G),z)=TRUE by A3,BVFUNC_1:def 19; hence thesis by A6,BINARITH:19; end; hence thesis; end; then All(u,PA,G) 'imp' All(u,PB,G) = I_el(Y) by BVFUNC_1:def 14; hence thesis by BVFUNC_1:19; end; theorem for u being Element of Funcs(Y,BOOLEAN), G being Subset of PARTITIONS(Y), PA,PB being a_partition of Y st u is_independent_of PA,G holds Ex(u,PA,G) '<' Ex(u,PB,G) proof let u be Element of Funcs(Y,BOOLEAN); let G be Subset of PARTITIONS(Y); let PA,PB be a_partition of Y; assume u is_independent_of PA,G; then A1: u is_dependent_of CompF(PA,G) by BVFUNC_2:def 8; A2:Ex(u,PA,G) = B_SUP(u,CompF(PA,G)) by BVFUNC_2:def 10; A3:Ex(u,PB,G) = B_SUP(u,CompF(PB,G)) by BVFUNC_2:def 10; for z being Element of Y holds Pj(Ex(u,PA,G) 'imp' Ex(u,PB,G),z) = TRUE proof let z be Element of Y; A4:z in EqClass(z,CompF(PA,G)) & EqClass(z,CompF(PA,G)) in CompF(PA,G) by T_1TOPSP:def 1; A5:z in EqClass(z,CompF(PB,G)) & EqClass(z,CompF(PB,G)) in CompF(PB,G) by T_1TOPSP:def 1; A6:Pj(Ex(u,PA,G) 'imp' Ex(u,PB,G),z) ='not' Pj(Ex(u,PA,G),z) 'or' Pj(Ex(u,PB,G),z) by BVFUNC_1:def 11; now per cases by MARGREL1:39; case Pj(Ex(u,PB,G),z)=TRUE; hence thesis by A6,BINARITH:19; case A7:Pj(Ex(u,PB,G),z)=FALSE; now assume (ex x being Element of Y st x in EqClass(z,CompF(PB,G)) & Pj(u,x)=TRUE); then Pj(Ex(u,PB,G),z)=TRUE by A3,BVFUNC_1:def 20; hence contradiction by A7,MARGREL1:43; end; then Pj(u,z)<>TRUE by A5; then not (ex x being Element of Y st x in EqClass(z,CompF(PA,G)) & Pj(u,x)=TRUE) by A1,A4,BVFUNC_1:def 18; then Pj(B_SUP(u,CompF(PA,G)),z) = FALSE by BVFUNC_1:def 20; then Pj(Ex(u,PA,G) 'imp' Ex(u,PB,G),z) =TRUE 'or' Pj(Ex(u,PB,G),z) by A2,A6,MARGREL1:41 .=TRUE by BINARITH:19; hence thesis; end; hence thesis; end; then Ex(u,PA,G) 'imp' Ex(u,PB,G) = I_el(Y) by BVFUNC_1:def 14; hence thesis by BVFUNC_1:19; end; theorem for a,b being Element of Funcs(Y,BOOLEAN), G being Subset of PARTITIONS(Y), PA being a_partition of Y holds All(a 'eqv' b,PA,G) '<' All(a,PA,G) 'eqv' All(b,PA,G) proof let a,b be Element of Funcs(Y,BOOLEAN); let G be Subset of PARTITIONS(Y); let PA be a_partition of Y; A1:All(a 'eqv' b,PA,G) = B_INF(a 'eqv' b,CompF(PA,G)) by BVFUNC_2:def 9; A2:All(a,PA,G) = B_INF(a,CompF(PA,G)) by BVFUNC_2:def 9; A3:All(b,PA,G) = B_INF(b,CompF(PA,G)) by BVFUNC_2:def 9; let z be Element of Y; assume A4:Pj(All(a 'eqv' b,PA,G),z)=TRUE; A5: now assume not (for x being Element of Y st x in EqClass(z,CompF(PA,G)) holds Pj(a 'eqv' b,x)=TRUE); then Pj(All(a 'eqv' b,PA,G),z)=FALSE by A1,BVFUNC_1:def 19; hence contradiction by A4,MARGREL1:43; end; A6:Pj(All(a,PA,G) 'eqv' All(b,PA,G),z) ='not' (Pj(All(a,PA,G),z) 'xor' Pj(All(b,PA,G),z)) by BVFUNC_1:def 12 .='not' (('not' Pj(All(a,PA,G),z) '&' Pj(All(b,PA,G),z)) 'or' (Pj(All(a,PA,G),z) '&' 'not' Pj(All(b,PA,G),z))) by BINARITH:def 2 .='not' ('not' Pj(All(a,PA,G),z) '&' Pj(All(b,PA,G),z)) '&' 'not' (Pj(All(a,PA,G),z) '&' 'not' Pj(All(b,PA,G),z)) by BINARITH:10 .=('not' 'not' Pj(All(a,PA,G),z) 'or' 'not' Pj(All(b,PA,G),z)) '&' 'not' (Pj(All(a,PA,G),z) '&' 'not' Pj(All(b,PA,G),z)) by BINARITH:9 .=('not' 'not' Pj(All(a,PA,G),z) 'or' 'not' Pj(All(b,PA,G),z)) '&' ('not' Pj(All(a,PA,G),z) 'or' 'not' 'not' Pj(All(b,PA,G),z)) by BINARITH:9 .=(Pj(All(a,PA,G),z) 'or' 'not' Pj(All(b,PA,G),z)) '&' ('not' Pj(All(a,PA,G),z) 'or' 'not' 'not' Pj(All(b,PA,G),z)) by MARGREL1:40 .=(Pj(All(a,PA,G),z) 'or' 'not' Pj(All(b,PA,G),z)) '&' ('not' Pj(All(a,PA,G),z) 'or' Pj(All(b,PA,G),z)) by MARGREL1:40 .=((Pj(All(a,PA,G),z) 'or' 'not' Pj(All(b,PA,G),z)) '&' 'not' Pj(All(a,PA,G),z)) 'or' ((Pj(All(a,PA,G),z) 'or' 'not' Pj(All(b,PA,G),z)) '&' Pj(All(b,PA,G),z)) by BINARITH:22 .=('not' Pj(All(a,PA,G),z) '&' Pj(All(a,PA,G),z) 'or' 'not' Pj(All(a,PA,G),z) '&' 'not' Pj(All(b,PA,G),z)) 'or' (Pj(All(b,PA,G),z) '&' (Pj(All(a,PA,G),z) 'or' 'not' Pj(All(b,PA,G),z))) by BINARITH:22 .=(('not' Pj(All(a,PA,G),z) '&' Pj(All(a,PA,G),z)) 'or' ('not' Pj(All(a,PA,G),z) '&' 'not' Pj(All(b,PA,G),z))) 'or' ((Pj(All(b,PA,G),z) '&' Pj(All(a,PA,G),z)) 'or' (Pj(All(b,PA,G),z) '&' 'not' Pj(All(b,PA,G),z))) by BINARITH:22 .=(FALSE 'or' ('not' Pj(All(a,PA,G),z) '&' 'not' Pj(All(b,PA,G),z))) 'or' ((Pj(All(b,PA,G),z) '&' Pj(All(a,PA,G),z)) 'or' (Pj(All(b,PA,G),z) '&' 'not' Pj(All(b,PA,G),z))) by MARGREL1:46 .=(FALSE 'or' ('not' Pj(All(a,PA,G),z) '&' 'not' Pj(All(b,PA,G),z))) 'or' ((Pj(All(b,PA,G),z) '&' Pj(All(a,PA,G),z)) 'or' FALSE) by MARGREL1:46 .=(('not' Pj(All(a,PA,G),z) '&' 'not' Pj(All(b,PA,G),z))) 'or' ((Pj(All(b,PA,G),z) '&' Pj(All(a,PA,G),z)) 'or' FALSE) by BINARITH:7 .=('not' Pj(All(a,PA,G),z) '&' 'not' Pj(All(b,PA,G),z)) 'or' (Pj(All(b,PA,G),z) '&' Pj(All(a,PA,G),z)) by BINARITH:7; per cases; suppose A7: (for x being Element of Y st x in EqClass(z,CompF(PA,G)) holds Pj(a,x)=TRUE) & (for x being Element of Y st x in EqClass(z,CompF(PA,G)) holds Pj(b,x)=TRUE); then A8:Pj(All(a,PA,G),z)=TRUE by A2,BVFUNC_1:def 19; Pj(B_INF(b,CompF(PA,G)),z) = TRUE by A7,BVFUNC_1:def 19; then Pj(All(a,PA,G) 'eqv' All(b,PA,G),z) =('not' TRUE '&' 'not' TRUE) 'or' TRUE by A3,A6,A8,MARGREL1:45 .=TRUE by BINARITH:19; hence thesis; suppose A9: (for x being Element of Y st x in EqClass(z,CompF(PA,G)) holds Pj(a,x)=TRUE) & not (for x being Element of Y st x in EqClass(z,CompF(PA,G)) holds Pj(b,x)=TRUE); then consider x1 being Element of Y such that A10: x1 in EqClass(z,CompF(PA,G)) & Pj(b,x1)<>TRUE; A11:Pj(b,x1)=FALSE by A10,MARGREL1:43; A12:Pj(a,x1)=TRUE by A9,A10; A13: Pj(a 'eqv' b,x1) ='not' (Pj(a,x1) 'xor' Pj(b,x1)) by BVFUNC_1:def 12 .='not' (('not' Pj(a,x1) '&' Pj(b,x1)) 'or' (Pj(a,x1) '&' 'not' Pj(b,x1))) by BINARITH:def 2 .='not' ('not' TRUE '&' FALSE) '&' 'not' (TRUE '&' 'not' FALSE) by A11,A12,BINARITH:10 .='not' (FALSE '&' FALSE) '&' 'not' (TRUE '&' 'not' FALSE) by MARGREL1:41 .='not' (FALSE '&' FALSE) '&' 'not' (TRUE '&' TRUE) by MARGREL1:41 .='not' FALSE '&' 'not' (TRUE '&' TRUE) by MARGREL1:45 .='not' FALSE '&' 'not' TRUE by MARGREL1:45 .=TRUE '&' 'not' TRUE by MARGREL1:41 .=TRUE '&' FALSE by MARGREL1:41 .=FALSE by MARGREL1:49; Pj(a 'eqv' b,x1)=TRUE by A5,A10; hence thesis by A13,MARGREL1:43; suppose A14: not (for x being Element of Y st x in EqClass(z,CompF(PA,G)) holds Pj(a,x)=TRUE) & (for x being Element of Y st x in EqClass(z,CompF(PA,G)) holds Pj(b,x)=TRUE); then consider x1 being Element of Y such that A15: x1 in EqClass(z,CompF(PA,G)) & Pj(a,x1)<>TRUE; A16:Pj(a,x1)=FALSE by A15,MARGREL1:43; A17:Pj(b,x1)=TRUE by A14,A15; A18: Pj(a 'eqv' b,x1) ='not' (Pj(a,x1) 'xor' Pj(b,x1)) by BVFUNC_1:def 12 .='not' (('not' Pj(a,x1) '&' Pj(b,x1)) 'or' (Pj(a,x1) '&' 'not' Pj(b,x1))) by BINARITH:def 2 .='not' ('not' FALSE '&' TRUE) '&' 'not' (FALSE '&' 'not' TRUE) by A16,A17,BINARITH:10 .='not' (TRUE '&' TRUE) '&' 'not' (FALSE '&' 'not' TRUE) by MARGREL1:41 .='not' (TRUE '&' TRUE) '&' 'not' (FALSE '&' FALSE) by MARGREL1:41 .='not' TRUE '&' 'not' (FALSE '&' FALSE) by MARGREL1:45 .='not' TRUE '&' 'not' FALSE by MARGREL1:45 .=FALSE '&' 'not' FALSE by MARGREL1:41 .=FALSE by MARGREL1:49; Pj(a 'eqv' b,x1)=TRUE by A5,A15; hence thesis by A18,MARGREL1:43; suppose A19: not (for x being Element of Y st x in EqClass(z,CompF(PA,G)) holds Pj(a,x)=TRUE) & not (for x being Element of Y st x in EqClass(z,CompF(PA,G)) holds Pj(b,x)=TRUE); then A20:Pj(All(a,PA,G),z)=FALSE by A2,BVFUNC_1:def 19; Pj(B_INF(b,CompF(PA,G)),z) = FALSE by A19,BVFUNC_1:def 19; then Pj(All(a,PA,G) 'eqv' All(b,PA,G),z) =(TRUE '&' 'not' FALSE) 'or' (FALSE '&' FALSE) by A3,A6,A20,MARGREL1:41 .=(TRUE '&' TRUE) 'or' (FALSE '&' FALSE) by MARGREL1:41 .=TRUE 'or' (FALSE '&' FALSE) by MARGREL1:45 .=TRUE by BINARITH:19; hence thesis; end; theorem for a,b being Element of Funcs(Y,BOOLEAN), G being Subset of PARTITIONS(Y), PA being a_partition of Y holds All(a '&' b,PA,G) '<' a '&' All(b,PA,G) proof let a,b be Element of Funcs(Y,BOOLEAN); let G be Subset of PARTITIONS(Y); let PA be a_partition of Y; A1:All(a '&' b,PA,G) = B_INF(a '&' b,CompF(PA,G)) by BVFUNC_2:def 9; A2:All(b,PA,G) = B_INF(b,CompF(PA,G)) by BVFUNC_2:def 9; let z be Element of Y; assume A3:Pj(All(a '&' b,PA,G),z)=TRUE; A4:z in EqClass(z,CompF(PA,G)) & EqClass(z,CompF(PA,G)) in CompF(PA,G) by T_1TOPSP:def 1; A5: now assume not (for x being Element of Y st x in EqClass(z,CompF(PA,G)) holds Pj(a '&' b,x)=TRUE); then Pj(All(a '&' b,PA,G),z)=FALSE by A1,BVFUNC_1:def 19; hence contradiction by A3,MARGREL1:43; end; now assume not (for x being Element of Y st x in EqClass(z,CompF(PA,G)) holds Pj(b,x)=TRUE); then consider x1 being Element of Y such that A6:x1 in EqClass(z,CompF(PA,G)) & Pj(b,x1)<>TRUE; A7:Pj(b,x1)=FALSE by A6,MARGREL1:43; Pj(a '&' b,x1)=TRUE by A5,A6; then A8:Pj(a,x1) '&' Pj(b,x1)=TRUE by VALUAT_1:def 6; Pj(a,x1) '&' Pj(b,x1) =FALSE by A7,MARGREL1:49; hence contradiction by A8,MARGREL1:43; end; then A9: Pj(B_INF(b,CompF(PA,G)),z) = TRUE by BVFUNC_1:def 19; now assume not (for x being Element of Y st x in EqClass(z,CompF(PA,G)) holds Pj(a,x)=TRUE); then consider x1 being Element of Y such that A10:x1 in EqClass(z,CompF(PA,G)) & Pj(a,x1)<>TRUE; A11:Pj(a,x1)=FALSE by A10,MARGREL1:43; Pj(a '&' b,x1)=TRUE by A5,A10; then A12:Pj(a,x1) '&' Pj(b,x1)=TRUE by VALUAT_1:def 6; Pj(a,x1) '&' Pj(b,x1) =FALSE by A11,MARGREL1:49; hence contradiction by A12,MARGREL1:43; end; then Pj(a,z)=TRUE by A4; then Pj(a '&' All(b,PA,G),z) =TRUE '&' TRUE by A2,A9,VALUAT_1:def 6 .=TRUE by MARGREL1:45; hence thesis; end; theorem for a,u being Element of Funcs(Y,BOOLEAN), G being Subset of PARTITIONS(Y), PA being a_partition of Y holds All(a,PA,G) 'imp' u '<' Ex(a 'imp' u,PA,G) proof let a,u be Element of Funcs(Y,BOOLEAN); let G be Subset of PARTITIONS(Y); let PA be a_partition of Y; A1:Ex(a 'imp' u,PA,G) = B_SUP(a 'imp' u,CompF(PA,G)) by BVFUNC_2:def 10; A2:All(a,PA,G) = B_INF(a,CompF(PA,G)) by BVFUNC_2:def 9; let z be Element of Y; assume Pj(All(a,PA,G) 'imp' u,z)=TRUE; then A3:'not' Pj(All(a,PA,G),z) 'or' Pj(u,z)=TRUE by BVFUNC_1:def 11; A4: ('not' Pj(All(a,PA,G),z))=TRUE or ('not' Pj(All(a,PA,G),z))=FALSE by MARGREL1:39; A5:z in EqClass(z,CompF(PA,G)) & EqClass(z,CompF(PA,G)) in CompF(PA,G) by T_1TOPSP:def 1; now per cases by A3,A4,BINARITH:7; case 'not' Pj(All(a,PA,G),z)=TRUE; then Pj(All(a,PA,G),z)=FALSE by MARGREL1:41; then Pj(All(a,PA,G),z)<>TRUE by MARGREL1:43; then consider x1 being Element of Y such that A6: x1 in EqClass(z,CompF(PA,G)) & Pj(a,x1)<>TRUE by A2,BVFUNC_1:def 19 ; now assume not (ex x being Element of Y st x in EqClass(z,CompF(PA,G)) & Pj(a 'imp' u,x)=TRUE); then Pj(a 'imp' u,x1)<>TRUE by A6; then Pj(a 'imp' u,x1)=FALSE by MARGREL1:43; then A7:('not' Pj(a,x1)) 'or' Pj(u,x1)=FALSE by BVFUNC_1:def 11; A8:Pj(u,x1)=TRUE or Pj(u,x1)=FALSE by MARGREL1:39; 'not' Pj(a,x1)=TRUE or 'not' Pj(a,x1)=FALSE by MARGREL1:39; then 'not' Pj(a,x1)=FALSE & Pj(u,x1)=FALSE by A7,A8,BINARITH:19; hence contradiction by A6,MARGREL1:41; end; hence thesis by A1,BVFUNC_1:def 20; case A9:Pj(u,z)=TRUE; now assume not (ex x being Element of Y st x in EqClass(z,CompF(PA,G)) & Pj(a 'imp' u,x)=TRUE); then Pj(a 'imp' u,z)<>TRUE by A5; then Pj(a 'imp' u,z)=FALSE by MARGREL1:43; then A10:('not' Pj(a,z)) 'or' Pj(u,z)=FALSE by BVFUNC_1:def 11; A11:Pj(u,z)=TRUE or Pj(u,z)=FALSE by MARGREL1:39; 'not' Pj(a,z)=TRUE or 'not' Pj(a,z)=FALSE by MARGREL1:39; then 'not' Pj(a,z)=FALSE & Pj(u,z)=FALSE by A10,A11,BINARITH:19; hence contradiction by A9,MARGREL1:43; end; hence thesis by A1,BVFUNC_1:def 20; end; hence thesis; end; theorem for a,b being Element of Funcs(Y,BOOLEAN), G being Subset of PARTITIONS(Y), PA being a_partition of Y holds (a 'eqv' b)=I_el(Y) implies (All(a,PA,G) 'eqv' All(b,PA,G))=I_el(Y) proof let a,b be Element of Funcs(Y,BOOLEAN); let G be Subset of PARTITIONS(Y); let PA be a_partition of Y; assume (a 'eqv' b)=I_el(Y); then (a 'imp' b)=I_el(Y) & (b 'imp' a)=I_el(Y) by Th10; then A1:'not' a 'or' b = I_el(Y) & 'not' b 'or' a = I_el(Y) by Th8; A2:All(a,PA,G) = B_INF(a,CompF(PA,G)) by BVFUNC_2:def 9; A3:All(b,PA,G) = B_INF(b,CompF(PA,G)) by BVFUNC_2:def 9; for z being Element of Y holds Pj(All(a,PA,G) 'eqv' All(b,PA,G),z)=TRUE proof let z be Element of Y; All(a,PA,G) 'eqv' All(b,PA,G) =(All(a,PA,G) 'imp' All(b,PA,G)) '&' (All(b,PA,G) 'imp' All(a,PA,G)) by Th7 .=('not' All(a,PA,G) 'or' All(b,PA,G)) '&' (All(b,PA,G) 'imp' All(a,PA,G)) by Th8 .=('not' All(a,PA,G) 'or' All(b,PA,G)) '&' ('not' All(b,PA,G) 'or' All(a,PA,G)) by Th8 .=(('not' All(a,PA,G) 'or' All(b,PA,G)) '&' 'not' All(b,PA,G)) 'or' (('not' All(a,PA,G) 'or' All(b,PA,G)) '&' All(a,PA,G)) by BVFUNC_1:15 .=(('not' All(a,PA,G) '&' 'not' All(b,PA,G)) 'or' (All(b,PA,G) '&' 'not' All(b,PA,G))) 'or' (('not' All(a,PA,G) 'or' All(b,PA,G)) '&' All(a,PA,G)) by BVFUNC_1:15 .=(('not' All(a,PA,G) '&' 'not' All(b,PA,G)) 'or' (All(b,PA,G) '&' 'not' All(b,PA,G))) 'or' (('not' All(a,PA,G) '&' All(a,PA,G)) 'or' (All(b,PA,G) '&' All(a,PA,G))) by BVFUNC_1:15 .=(('not' All(a,PA,G) '&' 'not' All(b,PA,G)) 'or' O_el(Y)) 'or' (('not' All(a,PA,G) '&' All(a,PA,G)) 'or' (All(b,PA,G) '&' All(a,PA,G))) by Th5 .=(('not' All(a,PA,G) '&' 'not' All(b,PA,G)) 'or' O_el(Y)) 'or' (O_el(Y) 'or' (All(b,PA,G) '&' All(a,PA,G))) by Th5 .=('not' All(a,PA,G) '&' 'not' All(b,PA,G)) 'or' (O_el(Y) 'or' (All(b,PA,G) '&' All(a,PA,G))) by BVFUNC_1:12 .=('not' All(a,PA,G) '&' 'not' All(b,PA,G)) 'or' (All(b,PA,G) '&' All(a,PA,G)) by BVFUNC_1:12; then A4:Pj(All(a,PA,G) 'eqv' All(b,PA,G),z) =Pj('not' All(a,PA,G) '&' 'not' All(b,PA,G),z) 'or' Pj( All(b,PA,G) '&' All(a,PA,G),z) by BVFUNC_1:def 7 .=(Pj('not' All(a,PA,G),z) '&' Pj('not' All(b,PA,G),z)) 'or' Pj( All(b,PA,G) '&' All(a,PA,G),z) by VALUAT_1:def 6 .=(Pj('not' All(a,PA,G),z) '&' Pj('not' All(b,PA,G),z)) 'or' (Pj( All(b,PA,G),z) '&' Pj( All(a,PA,G),z)) by VALUAT_1:def 6 .=('not' Pj(All(a,PA,G),z) '&' Pj('not' All(b,PA,G),z)) 'or' ( Pj(All(b,PA,G),z) '&' Pj( All(a,PA,G),z)) by VALUAT_1:def 5 .=('not' Pj(All(a,PA,G),z) '&' 'not' Pj(All(b,PA,G),z)) 'or' ( Pj(All(b,PA,G),z) '&' Pj(All(a,PA,G),z)) by VALUAT_1:def 5; A5:now assume A6: (for x being Element of Y st x in EqClass(z,CompF(PA,G)) holds Pj(a,x)=TRUE) & (for x being Element of Y st x in EqClass(z,CompF(PA,G)) holds Pj(b,x)=TRUE); then A7:Pj(All(a,PA,G),z) = TRUE by A2,BVFUNC_1:def 19; Pj(B_INF(b,CompF(PA,G)),z) = TRUE by A6,BVFUNC_1:def 19; then Pj(All(a,PA,G) 'eqv' All(b,PA,G),z) =('not' TRUE '&' 'not' TRUE) 'or' TRUE by A3,A4,A7,MARGREL1:45 .=TRUE by BINARITH:19; hence thesis; end; A8:now assume A9: (for x being Element of Y st x in EqClass(z,CompF(PA,G)) holds Pj(a,x)=TRUE) & not (for x being Element of Y st x in EqClass(z,CompF(PA,G)) holds Pj(b,x)=TRUE); then consider x1 being Element of Y such that A10:x1 in EqClass(z,CompF(PA,G)) & Pj(b,x1)<>TRUE; A11:Pj(b,x1)=FALSE by A10,MARGREL1:43; A12:Pj(a,x1)=TRUE by A9,A10; Pj('not' a 'or' b,x1) =Pj('not' a,x1) 'or' Pj(b,x1) by BVFUNC_1:def 7 .='not' TRUE 'or' FALSE by A11,A12,VALUAT_1:def 5 .=FALSE 'or' FALSE by MARGREL1:41 .=FALSE by BINARITH:7; then Pj('not' a 'or' b,x1)<>TRUE by MARGREL1:43; hence thesis by A1,BVFUNC_1:def 14; end; A13:now assume A14: not (for x being Element of Y st x in EqClass(z,CompF(PA,G)) holds Pj(a,x)=TRUE) & (for x being Element of Y st x in EqClass(z,CompF(PA,G)) holds Pj(b,x)=TRUE); then consider x1 being Element of Y such that A15:x1 in EqClass(z,CompF(PA,G)) & Pj(a,x1)<>TRUE; A16:Pj(a,x1)=FALSE by A15,MARGREL1:43; A17:Pj(b,x1)=TRUE by A14,A15; Pj('not' b 'or' a,x1) =Pj('not' b,x1) 'or' Pj(a,x1) by BVFUNC_1:def 7 .='not' TRUE 'or' FALSE by A16,A17,VALUAT_1:def 5 .=FALSE 'or' FALSE by MARGREL1:41 .=FALSE by BINARITH:7; then Pj('not' b 'or' a,x1)<>TRUE by MARGREL1:43; hence thesis by A1,BVFUNC_1:def 14; end; now assume A18: not (for x being Element of Y st x in EqClass(z,CompF(PA,G)) holds Pj(a,x)=TRUE) & not (for x being Element of Y st x in EqClass(z,CompF(PA,G)) holds Pj(b,x)=TRUE); then A19:Pj(All(a,PA,G),z) = FALSE by A2,BVFUNC_1:def 19; Pj(B_INF(b,CompF(PA,G)),z) = FALSE by A18,BVFUNC_1:def 19; then Pj(All(a,PA,G) 'eqv' All(b,PA,G),z) =(TRUE '&' 'not' FALSE) 'or' (FALSE '&' FALSE) by A3,A4,A19,MARGREL1:41 .=(TRUE '&' TRUE) 'or' (FALSE '&' FALSE) by MARGREL1:41 .=TRUE 'or' (FALSE '&' FALSE) by MARGREL1:45 .=TRUE by BINARITH:19; hence thesis; end; hence thesis by A5,A8,A13; end; hence thesis by BVFUNC_1:def 14; end; theorem for a,b being Element of Funcs(Y,BOOLEAN), G being Subset of PARTITIONS(Y), PA being a_partition of Y holds (a 'eqv' b)=I_el(Y) implies (Ex(a,PA,G) 'eqv' Ex(b,PA,G))=I_el(Y) proof let a,b be Element of Funcs(Y,BOOLEAN); let G be Subset of PARTITIONS(Y); let PA be a_partition of Y; assume (a 'eqv' b)=I_el(Y); then (a 'imp' b)=I_el(Y) & (b 'imp' a)=I_el(Y) by Th10; then A1:'not' a 'or' b = I_el(Y) & 'not' b 'or' a = I_el(Y) by Th8; A2:Ex(a,PA,G) = B_SUP(a,CompF(PA,G)) by BVFUNC_2:def 10; A3:Ex(b,PA,G) = B_SUP(b,CompF(PA,G)) by BVFUNC_2:def 10; for z being Element of Y holds Pj(Ex(a,PA,G) 'eqv' Ex(b,PA,G),z)=TRUE proof let z be Element of Y; Ex(a,PA,G) 'eqv' Ex(b,PA,G) =(Ex(a,PA,G) 'imp' Ex(b,PA,G)) '&' (Ex(b,PA,G) 'imp' Ex(a,PA,G)) by Th7 .=('not' Ex(a,PA,G) 'or' Ex(b,PA,G)) '&' (Ex(b,PA,G) 'imp' Ex(a,PA,G)) by Th8 .=('not' Ex(a,PA,G) 'or' Ex(b,PA,G)) '&' ('not' Ex(b,PA,G) 'or' Ex(a,PA,G)) by Th8 .=(('not' Ex(a,PA,G) 'or' Ex(b,PA,G)) '&' 'not' Ex(b,PA,G)) 'or' (('not' Ex(a,PA,G) 'or' Ex(b,PA,G)) '&' Ex(a,PA,G)) by BVFUNC_1:15 .=(('not' Ex(a,PA,G) '&' 'not' Ex(b,PA,G)) 'or' (Ex(b,PA,G) '&' 'not' Ex(b,PA,G))) 'or' (('not' Ex(a,PA,G) 'or' Ex(b,PA,G)) '&' Ex(a,PA,G)) by BVFUNC_1:15 .=(('not' Ex(a,PA,G) '&' 'not' Ex(b,PA,G)) 'or' (Ex(b,PA,G) '&' 'not' Ex(b,PA,G))) 'or' (('not' Ex(a,PA,G) '&' Ex(a,PA,G)) 'or' (Ex(b,PA,G) '&' Ex(a,PA,G))) by BVFUNC_1:15 .=(('not' Ex(a,PA,G) '&' 'not' Ex(b,PA,G)) 'or' O_el(Y)) 'or' (('not' Ex(a,PA,G) '&' Ex(a,PA,G)) 'or' (Ex(b,PA,G) '&' Ex(a,PA,G))) by Th5 .=(('not' Ex(a,PA,G) '&' 'not' Ex(b,PA,G)) 'or' O_el(Y)) 'or' (O_el(Y) 'or' (Ex(b,PA,G) '&' Ex(a,PA,G))) by Th5 .=('not' Ex(a,PA,G) '&' 'not' Ex(b,PA,G)) 'or' (O_el(Y) 'or' (Ex(b,PA,G) '&' Ex(a,PA,G))) by BVFUNC_1:12 .=('not' Ex(a,PA,G) '&' 'not' Ex(b,PA,G)) 'or' (Ex(b,PA,G) '&' Ex(a,PA,G)) by BVFUNC_1:12; then A4:Pj(Ex(a,PA,G) 'eqv' Ex(b,PA,G),z) =Pj('not' Ex(a,PA,G) '&' 'not' Ex(b,PA,G),z) 'or' Pj( Ex(b,PA,G) '&' Ex(a,PA,G),z) by BVFUNC_1:def 7 .=(Pj('not' Ex(a,PA,G),z) '&' Pj('not' Ex(b,PA,G),z)) 'or' Pj( Ex(b,PA,G) '&' Ex(a,PA,G),z) by VALUAT_1:def 6 .=(Pj('not' Ex(a,PA,G),z) '&' Pj('not' Ex(b,PA,G),z)) 'or' (Pj( Ex(b,PA,G),z) '&' Pj( Ex(a,PA,G),z)) by VALUAT_1:def 6 .=('not' Pj(Ex(a,PA,G),z) '&' Pj('not' Ex(b,PA,G),z)) 'or' ( Pj(Ex(b,PA,G),z) '&' Pj( Ex(a,PA,G),z)) by VALUAT_1:def 5 .=('not' Pj(Ex(a,PA,G),z) '&' 'not' Pj(Ex(b,PA,G),z)) 'or' ( Pj(Ex(b,PA,G),z) '&' Pj(Ex(a,PA,G),z)) by VALUAT_1:def 5; per cases; suppose A5: (ex x being Element of Y st x in EqClass(z,CompF(PA,G)) & Pj(a,x)=TRUE) & (ex x being Element of Y st x in EqClass(z,CompF(PA,G)) & Pj(b,x)=TRUE); then A6:Pj(Ex(a,PA,G),z) = TRUE by A2,BVFUNC_1:def 20; Pj(B_SUP(b,CompF(PA,G)),z) = TRUE by A5,BVFUNC_1:def 20; then Pj(Ex(a,PA,G) 'eqv' Ex(b,PA,G),z) =('not' TRUE '&' 'not' TRUE) 'or' TRUE by A3,A4,A6,MARGREL1:45 .=TRUE by BINARITH:19; hence thesis; suppose A7: (ex x being Element of Y st x in EqClass(z,CompF(PA,G)) & Pj(a,x)=TRUE) & not (ex x being Element of Y st x in EqClass(z,CompF(PA,G)) & Pj(b,x)=TRUE); then consider x1 being Element of Y such that A8:x1 in EqClass(z,CompF(PA,G)) & Pj(a,x1)=TRUE; Pj(b,x1)<>TRUE by A7,A8; then A9:Pj(b,x1)=FALSE by MARGREL1:43; Pj('not' a 'or' b,x1) =Pj('not' a,x1) 'or' Pj(b,x1) by BVFUNC_1:def 7 .='not' TRUE 'or' FALSE by A8,A9,VALUAT_1:def 5 .=FALSE 'or' FALSE by MARGREL1:41 .=FALSE by BINARITH:7; then Pj('not' a 'or' b,x1)<>TRUE by MARGREL1:43; hence thesis by A1,BVFUNC_1:def 14; suppose A10: not (ex x being Element of Y st x in EqClass(z,CompF(PA,G)) & Pj(a,x)=TRUE) & (ex x being Element of Y st x in EqClass(z,CompF(PA,G)) & Pj(b,x)=TRUE); then consider x1 being Element of Y such that A11:x1 in EqClass(z,CompF(PA,G)) & Pj(b,x1)=TRUE; Pj(a,x1)<>TRUE by A10,A11; then A12:Pj(a,x1)=FALSE by MARGREL1:43; Pj('not' b 'or' a,x1) =Pj('not' b,x1) 'or' Pj(a,x1) by BVFUNC_1:def 7 .='not' TRUE 'or' FALSE by A11,A12,VALUAT_1:def 5 .=FALSE 'or' FALSE by MARGREL1:41 .=FALSE by BINARITH:7; then Pj('not' b 'or' a,x1)<>TRUE by MARGREL1:43; hence thesis by A1,BVFUNC_1:def 14; suppose A13: not (ex x being Element of Y st x in EqClass(z,CompF(PA,G)) & Pj(a,x)=TRUE) & not (ex x being Element of Y st x in EqClass(z,CompF(PA,G)) & Pj(b,x)=TRUE); then A14:Pj(Ex(a,PA,G),z) = FALSE by A2,BVFUNC_1:def 20; Pj(B_SUP(b,CompF(PA,G)),z) = FALSE by A13,BVFUNC_1:def 20; then Pj(Ex(a,PA,G) 'eqv' Ex(b,PA,G),z) =(TRUE '&' 'not' FALSE) 'or' (FALSE '&' FALSE) by A3,A4,A14,MARGREL1:41 .=(TRUE '&' TRUE) 'or' (FALSE '&' FALSE) by MARGREL1:41 .=TRUE 'or' (FALSE '&' FALSE) by MARGREL1:45 .=TRUE by BINARITH:19; hence thesis; end; hence thesis by BVFUNC_1:def 14; end;