environ vocabulary FUNCT_2, MARGREL1, BVFUNC_1, ZF_LANG, FUNCT_1, RELAT_1, BINARITH, PARTIT1; notation TARSKI, XBOOLE_0, SUBSET_1, MARGREL1, VALUAT_1, RELAT_1, FUNCT_1, FRAENKEL, BINARITH, BVFUNC_1; constructors BINARITH, BVFUNC_1; clusters MARGREL1, VALUAT_1, BINARITH, FRAENKEL; requirements SUBSET, BOOLE; begin ::Chap. 1 Propositional Calculus reserve Y for non empty set; theorem :: BVFUNC_8:1 for a,b,c,d being Element of Funcs(Y,BOOLEAN) holds a 'imp' (b '&' c '&' d) = (a 'imp' b) '&' (a 'imp' c) '&' (a 'imp' d); theorem :: BVFUNC_8:2 for a,b,c,d being Element of Funcs(Y,BOOLEAN) holds a 'imp' (b 'or' c 'or' d) = (a 'imp' b) 'or' (a 'imp' c) 'or' (a 'imp' d); theorem :: BVFUNC_8:3 for a,b,c,d being Element of Funcs(Y,BOOLEAN) holds (a '&' b '&' c) 'imp' d = (a 'imp' d) 'or' (b 'imp' d) 'or' (c 'imp' d); theorem :: BVFUNC_8:4 for a,b,c,d being Element of Funcs(Y,BOOLEAN) holds (a 'or' b 'or' c) 'imp' d = (a 'imp' d) '&' (b 'imp' d) '&' (c 'imp' d); theorem :: BVFUNC_8:5 for a,b,c being Element of Funcs(Y,BOOLEAN) holds (a 'imp' b) '&' (b 'imp' c) '&' (c 'imp' a) = (a 'imp' b) '&' (b 'imp' c) '&' (c 'imp' a) '&' (b 'imp' a) '&' (a 'imp' c); theorem :: BVFUNC_8:6 for a,b being Element of Funcs(Y,BOOLEAN) holds a = (a '&' b) 'or' (a '&' 'not' b); theorem :: BVFUNC_8:7 for a,b being Element of Funcs(Y,BOOLEAN) holds a = (a 'or' b) '&' (a 'or' 'not' b); theorem :: BVFUNC_8:8 for a,b,c being Element of Funcs(Y,BOOLEAN) holds a = (a '&' b '&' c) 'or' (a '&' b '&' 'not' c) 'or' (a '&' 'not' b '&' c) 'or' (a '&' 'not' b '&' 'not' c); theorem :: BVFUNC_8:9 for a,b,c being Element of Funcs(Y,BOOLEAN) holds a = (a 'or' b 'or' c) '&' (a 'or' b 'or' 'not' c) '&' (a 'or' 'not' b 'or' c) '&' (a 'or' 'not' b 'or' 'not' c); theorem :: BVFUNC_8:10 for a,b being Element of Funcs(Y,BOOLEAN) holds a '&' b = a '&' ('not' a 'or' b); theorem :: BVFUNC_8:11 for a,b being Element of Funcs(Y,BOOLEAN) holds a 'or' b = a 'or' ('not' a '&' b); theorem :: BVFUNC_8:12 for a,b being Element of Funcs(Y,BOOLEAN) holds a 'xor' b = 'not'( a 'eqv' b); theorem :: BVFUNC_8:13 for a,b being Element of Funcs(Y,BOOLEAN) holds a 'xor' b = (a 'or' b) '&' ('not' a 'or' 'not' b); theorem :: BVFUNC_8:14 for a being Element of Funcs(Y,BOOLEAN) holds a 'xor' I_el(Y) = 'not' a; theorem :: BVFUNC_8:15 for a being Element of Funcs(Y,BOOLEAN) holds a 'xor' O_el(Y) = a; theorem :: BVFUNC_8:16 for a,b being Element of Funcs(Y,BOOLEAN) holds a 'xor' b = 'not' a 'xor' 'not' b; theorem :: BVFUNC_8:17 for a,b being Element of Funcs(Y,BOOLEAN) holds 'not'( a 'xor' b) = a 'xor' 'not' b; theorem :: BVFUNC_8:18 for a,b being Element of Funcs(Y,BOOLEAN) holds a 'eqv' b = (a 'or' 'not' b) '&' ('not' a 'or' b); theorem :: BVFUNC_8:19 for a,b being Element of Funcs(Y,BOOLEAN) holds a 'eqv' b = (a '&' b) 'or' ('not' a '&' 'not' b); theorem :: BVFUNC_8:20 for a being Element of Funcs(Y,BOOLEAN) holds a 'eqv' I_el(Y) = a; theorem :: BVFUNC_8:21 for a being Element of Funcs(Y,BOOLEAN) holds a 'eqv' O_el(Y) = 'not' a; theorem :: BVFUNC_8:22 for a,b being Element of Funcs(Y,BOOLEAN) holds 'not'( a 'eqv' b) = (a 'eqv' 'not' b); theorem :: BVFUNC_8:23 for a,b being Element of Funcs(Y,BOOLEAN) holds 'not' a '<' (a 'imp' b) 'eqv' 'not' a; theorem :: BVFUNC_8:24 for a,b being Element of Funcs(Y,BOOLEAN) holds 'not' a '<' (b 'imp' a) 'eqv' 'not' b; theorem :: BVFUNC_8:25 for a,b being Element of Funcs(Y,BOOLEAN) holds a '<' (a 'or' b) 'eqv' (b 'or' a) 'eqv' a; theorem :: BVFUNC_8:26 for a being Element of Funcs(Y,BOOLEAN) holds a 'imp' ('not' a 'eqv' 'not' a) = I_el(Y); theorem :: BVFUNC_8:27 for a,b being Element of Funcs(Y,BOOLEAN) holds ((a 'imp' b) 'imp' a) 'imp' a = I_el(Y); theorem :: BVFUNC_8:28 for a,b,c,d being Element of Funcs(Y,BOOLEAN) holds ((a 'imp' c) '&' (b 'imp' d)) '&' ('not' c 'or' 'not' d) 'imp' ('not' a 'or' 'not' b)=I_el(Y); theorem :: BVFUNC_8:29 for a,b,c being Element of Funcs(Y,BOOLEAN) holds (a 'imp' b) 'imp' ((a 'imp' (b 'imp' c)) 'imp' (a 'imp' c)) = I_el(Y);