Copyright (c) 1989 Association of Mizar Users
environ vocabulary VECTSP_1, RLVECT_1, BINOP_1, FUNCT_1, RELAT_1, ARYTM_1, SYMSP_1; notation TARSKI, XBOOLE_0, ZFMISC_1, SUBSET_1, FUNCT_1, FUNCT_2, DOMAIN_1, STRUCT_0, RLVECT_1, BINOP_1, VECTSP_1, RELSET_1; constructors DOMAIN_1, BINOP_1, VECTSP_1, MEMBERED, XBOOLE_0; clusters STRUCT_0, RELSET_1, SUBSET_1, VECTSP_1, MEMBERED, ZFMISC_1, XBOOLE_0; requirements SUBSET, BOOLE; definitions TARSKI, STRUCT_0; theorems BINOP_1, VECTSP_1, TARSKI, RELSET_1, ZFMISC_1, RLVECT_1; schemes BINOP_1, FUNCT_2, XBOOLE_0; begin :: 1. SYMPLECTIC VECTOR SPACE STRUCTURE reserve F for Field; definition let F; struct (VectSpStr over F) SymStr over F (# carrier -> set, add -> BinOp of the carrier, Zero -> Element of the carrier, lmult -> Function of [:the carrier of F, the carrier:], the carrier, 2_arg_relation -> Relation of the carrier #); end; definition let F; cluster non empty SymStr over F; existence proof consider X being non empty set, a being BinOp of X, Z being Element of X, l being Function of [:the carrier of F, X:], X, r being Relation of X; take SymStr(#X,a,Z,l,r#); thus the carrier of SymStr(#X,a,Z,l,r#) is non empty; end; end; definition let F; let S be SymStr over F; let a,b be Element of S; pred a _|_ b means :Def1: [a,b] in the 2_arg_relation of S; end; set X = {0}; reconsider o = 0 as Element of {0} by TARSKI:def 1; deffunc F(Element of {0},Element of {0}) = o; consider md being BinOp of {0} such that Lm1: for x,y being Element of {0} holds md.(x,y) = F(x,y) from BinOpLambda; Lm2: now let F; set CV = [:X,X:]; defpred P[set] means ex a,b being Element of X st $1 = [a,b] & b = o; consider mo being set such that A1: for x being set holds x in mo iff x in CV & P[x] from Separation; mo c= CV proof let x be set; thus thesis by A1; end; then reconsider mo as Relation of X by RELSET_1:def 1; take mo; thus for x being set holds x in mo iff x in CV & ex a,b being Element of X st x = [a,b] & b = o by A1; end; definition let F; let X be non empty set, md be BinOp of X, o be Element of X, mF be Function of [:the carrier of F, X:], X, mo be Relation of X; cluster SymStr (# X,md,o,mF,mo #) -> non empty; coherence proof thus the carrier of SymStr (# X,md,o,mF,mo #) is non empty; end; end; Lm3: for mF being Function of [:the carrier of F,X:],X, mo being Relation of X holds SymStr (# X,md,o,mF,mo #) is Abelian add-associative right_zeroed right_complementable proof let mF be Function of [:the carrier of F,X:],X; let mo be Relation of X; set H = SymStr (# X,md,o,mF,mo #); A1: for x,y being Element of H holds x+y = y+x proof let x,y be Element of H; A2: y+x = md.(y,x) by RLVECT_1:5; reconsider x,y as Element of X; md.(x,y) = o & md.(y,x) = o by Lm1; hence thesis by A2,RLVECT_1:5; end; A3: for x,y,z being Element of H holds (x+y)+z = x+(y+z) proof let x,y,z be Element of H; A4: (x+y)+z = md.((x+y),z) by RLVECT_1:5; x+(y+z) = md.(x,(y+z)) by RLVECT_1:5; then A5: x+(y+z) = md.(x,md.(y,z)) by RLVECT_1:5; reconsider x,y,z as Element of X; md.(x,md.(y,z)) = o by Lm1; hence thesis by A4,A5,Lm1; end; A6: for x being Element of H holds x+0.H = x proof let x be Element of H; A7: x+0.H = md.(x,0.H) by RLVECT_1:5; reconsider x as Element of X; md.(x,0.H) = o by Lm1; hence thesis by A7,TARSKI:def 1; end; for x being Element of H ex y being Element of H st x+y = 0.H proof let x be Element of H; A8: x+(-x) = md.(x,(-x)) by RLVECT_1:5; A9: 0.H = o by RLVECT_1:def 2; take -x; thus thesis by A8,A9,Lm1; end; hence thesis by A1,A3,A6,VECTSP_1:7; end; definition let F; cluster Abelian add-associative right_zeroed right_complementable (non empty SymStr over F); existence proof consider mF being Function of [:the carrier of F,X:],X; consider mo being Relation of X; SymStr (# X,md,o,mF,mo #) is Abelian add-associative right_zeroed right_complementable by Lm3; hence thesis; end; end; Lm4: now let F; let mF be Function of [:the carrier of F,X:],X such that A1: for a being Element of F for x being Element of X holds mF.[a,x] = o; let mo be Relation of X; let MPS be Abelian add-associative right_zeroed right_complementable (non empty SymStr over F) such that A2: MPS = SymStr (# X,md,o,mF,mo #); thus MPS is VectSp-like proof for x,y being Element of F for v,w being Element of MPS holds x*(v+w) = x*v+x*w & (x+y)*v = x*v+y*v & (x*y)*v = x*(y*v) & (1_ F)*v = v proof let x,y be Element of F; let v,w be Element of MPS; A3: x*(v+w) = x*v+x*w proof A4: v+w = md.(v,w) by A2,RLVECT_1:5; reconsider v,w as Element of X by A2; A5: md.(v,w) = o by Lm1; reconsider v,w as Element of MPS; A6: x*(v+w) = mF.(x,o) by A2,A4,A5,VECTSP_1:def 24; mF.(x,o) = mF.[x,o] by BINOP_1:def 1; then A7: x*(v+w) = o by A1,A6; mF.(x,v) = mF.[x,v] by BINOP_1:def 1; then mF.(x,v) = o by A1; then A8: x*v = o by A2,VECTSP_1:def 24; mF.(x,w) = mF.[x,w] by BINOP_1:def 1; then mF.(x,w) = o by A1; then A9: x*w = o by A2,VECTSP_1:def 24; o = 0.MPS by A2,RLVECT_1:def 2; hence thesis by A7,A8,A9,RLVECT_1:10; end; A10: (x+y)*v = x*v+y*v proof set z = x+y; A11: z*v = mF.(z,v) by A2,VECTSP_1:def 24; reconsider v as Element of MPS; A12: mF.(z,v) = mF.[z,v] by BINOP_1:def 1; reconsider v as Element of MPS; A13: (x+y)*v = o by A1,A2,A11,A12; reconsider v as Element of MPS; mF.(x,v) = mF.[x,v] by BINOP_1:def 1; then A14: mF.(x,v) = o by A1,A2; reconsider v as Element of MPS; A15: x*v = o by A2,A14,VECTSP_1:def 24; reconsider v as Element of MPS; mF.(y,v) = mF.[y,v] by BINOP_1:def 1; then A16: mF.(y,v) = o by A1,A2; reconsider v as Element of MPS; A17: y*v = o by A2,A16,VECTSP_1:def 24; o = 0.MPS by A2,RLVECT_1:def 2; hence thesis by A13,A15,A17,RLVECT_1:10; end; A18: (x*y)*v = x*(y*v) proof set z = x*y; A19: z*v = mF.(z,v) by A2,VECTSP_1:def 24; reconsider v as Element of MPS; A20: mF.(z,v) = mF.[z,v] by BINOP_1:def 1; reconsider v as Element of MPS; A21: (x*y)*v = o by A1,A2,A19,A20; reconsider v as Element of MPS; mF.(y,v) = mF.[y,v] by BINOP_1:def 1; then A22: mF.(y,v) = o by A1,A2; reconsider v as Element of MPS; y*v = o by A2,A22,VECTSP_1:def 24; then A23: x*(y*v) = mF.(x,o) by A2,VECTSP_1:def 24; mF.(x,o) = mF.[x,o] by BINOP_1:def 1; hence thesis by A1,A21,A23; end; (1_ F)*v = v proof set one = 1_ F; A24: one*v = mF.(one,v) by A2,VECTSP_1:def 24; A25: mF.(one,v) = mF.[one,v] by BINOP_1:def 1; reconsider v as Element of MPS; mF.(one,v) = o by A1,A2,A25; hence thesis by A2,A24,TARSKI:def 1; end; hence thesis by A3,A10,A18; end; hence thesis by VECTSP_1:def 26; end; end; Lm5: now let F; let mF be Function of [:the carrier of F,X:],X such that for a being Element of F for x being Element of X holds mF.[a,x] = o; set CV = [:X,X:]; let mo be Relation of X such that A1: for x being set holds x in mo iff x in CV & ex a,b being Element of X st x = [a,b] & b = o; let MPS be Abelian add-associative right_zeroed right_complementable (non empty SymStr over F) such that A2: MPS = SymStr (# X,md,o,mF,mo #); A3: for a,b being Element of MPS holds a _|_ b iff [a,b] in CV & ex c,d being Element of X st [a,b] = [c,d] & d = o proof let a,b be Element of MPS; a _|_ b iff [a,b] in mo by A2,Def1; hence thesis by A1; end; A4: for a,b being Element of MPS holds a _|_ b iff b = o proof let a,b be Element of MPS; A5: a _|_ b implies b = o proof assume a _|_ b; then ex c,d being Element of X st [a,b] = [c,d] & d = o by A3; hence thesis by ZFMISC_1:33; end; b = o implies a _|_ b proof assume A6: b = o; consider c,d being Element of MPS such that A7: c = a & d = b; [a,b] = [c,d] by A7; hence thesis by A2,A3,A6; end; hence thesis by A5; end; 0.MPS = o by A2,TARSKI:def 1; hence for a being Element of MPS holds (a <> 0.MPS implies (ex p being Element of MPS st not p _|_ a)) by A2,TARSKI:def 1; thus for a,b being Element of MPS for l being Element of F holds (a _|_ b implies l*a _|_ b) proof let a,b be Element of MPS; let l be Element of F; assume a _|_ b; then b = o by A4; hence thesis by A4; end; thus for a,b,c being Element of MPS holds (b _|_ a & c _|_ a implies b+c _|_ a) proof let a,b,c be Element of MPS; assume b _|_ a & c _|_ a; then a = o by A4; hence thesis by A4; end; thus for a,b,x being Element of MPS holds ( not b _|_ a implies ex k being Element of F st x-k*b _|_ a) proof let a,b,x be Element of MPS; assume A8: not b _|_ a; assume not thesis; a <> o by A4,A8; hence contradiction by A2,TARSKI:def 1; end; let a,b,c be Element of MPS; assume a _|_ b+c & b _|_ c+a; assume not c _|_ a+b; then a+b <> o by A4; hence contradiction by A2,TARSKI:def 1; end; :: 2. SYMPLECTIC VECTOR SPACE definition let F; let IT be Abelian add-associative right_zeroed right_complementable (non empty SymStr over F); attr IT is SymSp-like means :Def2: for a,b,c,x being Element of IT for l being Element of F holds (a<>(0.IT) implies ( ex y being Element of the carrier of IT st not y _|_ a )) & (a _|_ b implies l*a _|_ b) & ( b _|_ a & c _|_ a implies b+c _|_ a ) & (not b _|_ a implies (ex k being Element of F st x-k*b _|_ a)) & (a _|_ b+c & b _|_ c+a implies c _|_ a+b ); end; definition let F; cluster SymSp-like VectSp-like strict (Abelian add-associative right_zeroed right_complementable (non empty SymStr over F)); existence proof deffunc F(Element of F, Element of X) = o; consider mF being Function of [:the carrier of F,X:],X such that A1: for a being Element of F for x being Element of X holds mF.[a,x] = F(a,x) from Lambda2D; consider mo being Relation of X such that A2: for x being set holds x in mo iff x in [:X,X:] & ex a,b being Element of X st x = [a,b] & b = o by Lm2; reconsider MPS = SymStr (# X,md,o,mF,mo #) as Abelian add-associative right_zeroed right_complementable (non empty SymStr over F) by Lm3; take MPS; thus for a,b,c,x being Element of MPS for l being Element of F holds (a<>(0.MPS) implies ( ex y being Element of the carrier of MPS st not y _|_ a )) & (a _|_ b implies l*a _|_ b) & ( b _|_ a & c _|_ a implies b+c _|_ a ) & (not b _|_ a implies (ex k being Element of F st x-k*b _|_ a)) & (a _|_ b+c & b _|_ c+a implies c _|_ a+b ) by A1,A2,Lm5; thus MPS is VectSp-like by A1,Lm4; thus thesis; end; end; definition let F; mode SymSp of F is SymSp-like VectSp-like (Abelian add-associative right_zeroed right_complementable (non empty SymStr over F)); end; reserve S for SymSp of F; reserve a,b,c,d,a',b',p,q,r,s,x,y,z for Element of S; reserve k,l for Element of F; canceled 10; theorem Th11: 0.S _|_ a proof set 0V = 0.S, 0F = 0.F; A1: now assume a _|_ a; then 0F*a _|_ a by Def2; hence 0.S _|_ a by VECTSP_1:59; end; now assume not a _|_ a; then consider m being Element of F such that A2:(0V-m*a) _|_ a by Def2; 0F*(0V-m*a) _|_ a by A2,Def2; hence 0V _|_ a by VECTSP_1:59; end; hence thesis by A1; end; theorem Th12: a _|_ b implies b _|_ a proof set 0V = 0.S; assume a _|_ b; then a _|_ 0V+b & 0V _|_ b+a by Th11,RLVECT_1:10; then b _|_ a+0V by Def2; hence thesis by RLVECT_1:10; end; theorem Th13: not a _|_ b & c+a _|_ b implies not c _|_ b proof assume A1:not a _|_ b & c+a _|_ b; assume not thesis; then (-1_ F)*c _|_ b by Def2; then -c _|_ b by VECTSP_1:59; then -c+(c+a) _|_ b by A1,Def2; then (c+(-c))+a _|_ b by RLVECT_1:def 6; then 0.S+a _|_ b by RLVECT_1:16; hence contradiction by A1,RLVECT_1:10; end; theorem Th14: not b _|_ a & c _|_ a implies not b+c _|_ a proof assume A1:not b _|_ a & c _|_ a; assume A2:not thesis; (-1_ F)*c _|_ a by A1,Def2; then -c _|_ a by VECTSP_1:59; then (b+c)+(-c) _|_ a by A2,Def2; then b+(c+(-c)) _|_ a by RLVECT_1:def 6; then b+0.S _|_ a by RLVECT_1:16; hence contradiction by A1,RLVECT_1:10; end; theorem Th15: not b _|_ a & not l=0.F implies not l*b _|_ a & not b _|_ l*a proof set 1F = 1_ F; assume A1: not b _|_ a & not l=0.F; A2:now assume A3:l*b _|_ a; consider k such that A4:l*k=1F by A1,VECTSP_1:def 20; k*(l*b) _|_ a by A3,Def2; then 1F*b _|_ a by A4,VECTSP_1:def 26; hence contradiction by A1,VECTSP_1:def 26; end; now assume b _|_ l*a; then A5:l*a _|_ b by Th12; consider k such that A6:l*k=1F by A1,VECTSP_1:def 20; k*(l*a) _|_ b by A5,Def2; then 1F*a _|_ b by A6,VECTSP_1:def 26; then a _|_ b by VECTSP_1:def 26; hence contradiction by A1,Th12; end; hence thesis by A2; end; theorem Th16: a _|_ b implies -a _|_ b proof assume a _|_ b; then (-1_ F)*a _|_ b by Def2; hence thesis by VECTSP_1:59; end; canceled 2; theorem Th19: not a _|_ c implies not a+b _|_ c or not (1_ F+1_ F)*a+b _|_ c proof set 1F = 1_ F; assume A1: not a _|_ c; assume not thesis; then a+b _|_ c & (1F*a+1_ F*a)+b _|_ c by VECTSP_1:def 26; then a+b _|_ c & (a+1F*a)+b _|_ c by VECTSP_1:def 26; then a+b _|_ c & (a+a)+b _|_ c by VECTSP_1:def 26; then a+(a+b) _|_ c & (a+b) _|_ c by RLVECT_1:def 6; hence contradiction by A1,Th14; end; theorem Th20: not a' _|_ a & a' _|_ b & not b' _|_ b & b' _|_ a implies not a'+b' _|_ a & not a'+b' _|_ b proof set 0V = 0.S; assume A1: not a' _|_ a & a' _|_ b & not b' _|_ b & b' _|_ a; assume not thesis; then (a'+b' _|_ a & (-(1_ F))*b' _|_ a) or (a'+b' _|_ b & (-(1_ F))*a' _|_ b) by A1,Def2; then (a'+b' _|_ a & -b' _|_ a) or (a'+b' _|_ b & -a' _|_ b) by VECTSP_1:59; then (a'+b')+(-b') _|_ a or -a'+(a'+b') _|_ b by Def2; then a'+(b'+(-b')) _|_ a or (-a'+a')+b' _|_ b by RLVECT_1:def 6; then a'+0V _|_ a or 0V+b' _|_ b by RLVECT_1:16; hence contradiction by A1,RLVECT_1:10; end; theorem Th21: a<>0.S & b<>0.S implies ex p st not p _|_ a & not p _|_ b proof assume A1: a<>0.S & b<>0.S; then consider a' such that A2: not a' _|_ a by Def2; now assume A3: a' _|_ b; consider b' such that A4: not b' _|_ b by A1,Def2; now assume b' _|_ a; then not a'+b' _|_ a & not a'+b' _|_ b by A2,A3,A4,Th20; hence thesis; end; hence thesis by A4; end; hence thesis by A2; end; theorem Th22: 1_ F+1_ F<>0.F & a<>0.S & b<>0.S & c <>0.S implies ex p st not p _|_ a & not p _|_ b & not p _|_ c proof assume A1: 1_ F+1_ F<>0.F & a<>0.S & b<>0.S & c <>0.S; then consider r such that A2: not r _|_ a & not r _|_ b by Th21; consider s such that A3: not s _|_ a & not s _|_ c by A1,Th21; now assume that A4: r _|_ c and A5: s _|_ b; A6: now assume A7: not r+s _|_ a; not r+s _|_ b & not r+s _|_ c by A2,A3,A4,A5,Th14; hence thesis by A7; end; now assume A8: not (1_ F+1_ F)*r+s _|_ a; not (1_ F+1_ F)*r+s _|_ b & not (1_ F+1_ F)*r+s _|_ c proof not (1_ F+1_ F)*r _|_ b & (1_ F+1_ F)*r _|_ c by A1,A2,A4,Def2,Th15; hence thesis by A3,A5,Th14; end; hence thesis by A8; end; hence thesis by A2,A6,Th19; end; hence thesis by A2,A3; end; theorem Th23: a-b _|_ d & a-c _|_ d implies b-c _|_ d proof assume a-b _|_ d & a-c _|_ d; then -(a-b) _|_ d & a-c _|_ d by Th16; then -a+b _|_ d & a-c _|_ d by VECTSP_1:64; then b+(-a)+(a-c) _|_ d by Def2; then b+((-a)+(a-c)) _|_ d by RLVECT_1:def 6; then b+(-a+(a+(-c))) _|_ d by RLVECT_1:def 11; then b+((-a+a)+(-c)) _|_ d by RLVECT_1:def 6; then b+((0.S)+(-c)) _|_ d by RLVECT_1:16; then b+(-c) _|_ d by RLVECT_1:10; hence thesis by RLVECT_1:def 11; end; theorem Th24: not b _|_ a & x-k*b _|_ a & x-l*b _|_ a implies k = l proof assume A1:not b _|_ a & x-k*b _|_ a & x-l*b _|_ a; assume A2:not thesis; set 1F=1_ F; k*b-l*b _|_ a by A1,Th23; then k*b+(-l*b) _|_ a by RLVECT_1:def 11; then k*b+((-1F)*(l*b)) _|_ a by VECTSP_1:59; then k*b+(((-1F)*l)*b) _|_ a by VECTSP_1:def 26; then k*b+(-(l*(1F)))*b _|_ a by VECTSP_1:41; then k*b+(-l)*b _|_ a by VECTSP_1:def 19; then (k+(-l))*b _|_ a by VECTSP_1:def 26; then (k+(-l))"*((k+(-l))*b) _|_ a by Def2; then A3: ((k+(-l))"*(k+(-l)))*b _|_ a by VECTSP_1:def 26; k-l<>0.F by A2,RLVECT_1:35; then k+(-l)<>0.F by RLVECT_1:def 11; then (1F)*b _|_ a by A3,VECTSP_1:def 22; hence contradiction by A1,VECTSP_1:def 26; end; theorem Th25: 1_ F+1_ F<>0.F implies a _|_ a proof assume A1: 1_ F+1_ F<>0.F; set 1F = 1_ F; now assume a <> 0.S; then consider c such that A2: not c _|_ a by Def2; consider k such that A3: a-k*c _|_ a by A2,Def2; a _|_ a-k*c by A3,Th12; then a _|_ a+(-k*c) & a _|_ (-k*c)+a by RLVECT_1:def 11; then -k*c _|_ a+a by Def2; then -k*c _|_ a+(1F)*a by VECTSP_1:def 26; then -k*c _|_ (1F)*a+(1F)*a by VECTSP_1:def 26; then (-1F)*(k*c) _|_ (1F)*a+(1F)*a by VECTSP_1:59; then (-1F)*(k*c) _|_ ((1F)+(1F))*a by VECTSP_1:def 26; then ((-1F)*k)*c _|_ ((1F)+(1F))*a by VECTSP_1:def 26; then (-(k*(1F)))*c _|_ ((1F)+(1F))*a by VECTSP_1:41; then (-k)*c _|_ ((1_ F)+(1F))*a by VECTSP_1:def 19; then ((1_ F)+(1_ F))*a _|_ (-k)*c by Th12; then ((1_ F)+(1_ F))"*(((1_ F)+(1_ F))*a) _|_ (-k)*c by Def2; then a _|_ (-k)*c by A1,VECTSP_1:67; then A4: (-k)*c _|_ a by Th12; a+(-k)*c _|_ a by A3,VECTSP_1:68; hence thesis by A4,Th14; end; hence thesis by Th11; end; :: :: 5. ORTHOGONAL PROJECTION :: definition let F; let S,a,b,x; assume A1: not b _|_ a; canceled 3; func ProJ(a,b,x) -> Element of F means :Def6: for l being Element of F st x-l*b _|_ a holds it = l; existence proof consider k being Element of F such that A2: x-k*b _|_ a by A1,Def2; take k; let l be Element of F; assume x-l*b _|_ a; hence thesis by A1,A2,Th24; end; uniqueness proof let l1,l2 be Element of F such that A3: for l being Element of F st x-l*b _|_ a holds l1 = l and A4: for l being Element of F st x-l*b _|_ a holds l2 = l; consider k being Element of F such that A5: x-k*b _|_ a by A1,Def2; l1 = k by A3,A5; hence thesis by A4,A5; end; end; canceled; theorem Th27: not b _|_ a implies x-ProJ(a,b,x)*b _|_ a proof assume A1: not b _|_ a; then ex l being Element of F st x-l*b _|_ a by Def2; hence thesis by A1,Def6; end; theorem Th28: not b _|_ a implies ProJ(a,b,l*x) = l*ProJ(a,b,x) proof assume A1: not b _|_ a; set L = x-ProJ(a,b,x)*b; A2: L _|_ a by A1,Th27; l*L = l*x-l*(ProJ(a,b,x)*b) by VECTSP_1:70 .= l*x-(l*ProJ(a,b,x))*b by VECTSP_1:def 26; then A3: l*x-(l*ProJ(a,b,x))*b _|_ a by A2,Def2; l*x - ProJ(a,b,l*x)*b _|_ a by A1,Th27; hence thesis by A1,A3,Th24; end; theorem Th29:not b _|_ a implies ProJ(a,b,x+y) = ProJ(a,b,x) + ProJ(a,b,y) proof set 1F = 1_ F; assume A1: not b _|_ a; then A2: x-ProJ(a,b,x)*b _|_ a & y-ProJ(a,b,y)*b _|_ a by Th27; set L = (x-ProJ(a,b,x)*b)+(y-ProJ(a,b,y)*b); A3: L _|_ a by A2,Def2; A4: now thus L = (x+(-ProJ(a,b,x)*b))+(y-ProJ(a,b,y)*b) by RLVECT_1:def 11 .= (x+(-ProJ(a,b,x)*b))+(y+(-ProJ(a,b,y)*b)) by RLVECT_1:def 11 .= (((-ProJ(a,b,x)*b)+x)+y)+(-ProJ(a,b,y)*b) by RLVECT_1:def 6 .= ((x+y)+(-ProJ(a,b,x)*b))+(-ProJ(a,b,y)*b) by RLVECT_1:def 6 .= (x+y)+((-ProJ(a,b,x)*b)+(-ProJ(a,b,y)*b)) by RLVECT_1:def 6 .= (x+y)+((1F)*(-ProJ(a,b,x)*b)+(-ProJ(a,b,y)*b)) by VECTSP_1:def 26 .= (x+y)+((1F)*(-ProJ(a,b,x)*b)+(1F)*(-ProJ (a,b,y)*b)) by VECTSP_1:def 26 .= (x+y)+((1F)*((-ProJ(a,b,x))*b)+(1F)*(-ProJ(a,b,y)*b)) by VECTSP_1:68 .= (x+y)+((1F)*((-ProJ(a,b,x))*b)+(1F)*((-ProJ (a,b,y))*b)) by VECTSP_1:68 .= (x+y)+(((1F)*(-ProJ(a,b,x)))*b+(1F)*((-ProJ (a,b,y))*b)) by VECTSP_1:def 26 .= (x+y)+(((-ProJ(a,b,x))*(1F))*b+((1F)*(-ProJ(a,b,y)))*b) by VECTSP_1: def 26 .= (x+y)+((-ProJ(a,b,x))*b+((-ProJ(a,b,y))*(1F))*b) by VECTSP_1:def 19 .= (x+y)+((-ProJ(a,b,x))*b+(-ProJ(a,b,y))*b) by VECTSP_1:def 19 .= (x+y)+((-ProJ(a,b,x))+(-ProJ(a,b,y)))*b by VECTSP_1:def 26 .= (x+y)+(-(ProJ(a,b,x)+ProJ(a,b,y)))*b by RLVECT_1:45 .= (x+y)-(ProJ(a,b,x)+ProJ(a,b,y))*b by VECTSP_1:68; end; (x+y)-ProJ(a,b,x+y)*b _|_ a by A1,Th27; hence thesis by A1,A3,A4,Th24; end; theorem not b _|_ a & l <> 0.F implies ProJ(a,l*b,x) = l"*ProJ(a,b,x) proof assume that A1: not b _|_ a and A2: l <> 0.F; A3: x-ProJ(a,b,x)*b _|_ a by A1,Th27; A4: not l*b _|_ a by A1,A2,Th15; set L = x-ProJ(a,l*b,x)*(l*b); A5: L _|_ a by A4,Th27; L = x-(ProJ(a,l*b,x)*l)*b by VECTSP_1:def 26; then ProJ(a,b,x)*l" = (ProJ(a,l*b,x)*l)*l" by A1,A3,A5,Th24; then ProJ(a,b,x)*l" = ProJ(a,l*b,x)*(l*l") by VECTSP_1:def 16; then l"*ProJ(a,b,x) = ProJ(a,l*b,x)*(1_ F) by A2,VECTSP_1:def 22; hence thesis by VECTSP_1:def 19; end; theorem Th31: not b _|_ a & l <> 0.F implies ProJ(l*a,b,x) = ProJ(a,b,x) proof assume that A1: not b _|_ a and A2: l <> 0.F; not b _|_ l*a by A1,A2,Th15; then A3: x-ProJ(a,b,x)*b _|_ a & x-ProJ(l*a,b,x)*b _|_ l*a by A1,Th27; then l*a _|_ x-ProJ(l*a,b,x)*b by Th12; then l"*(l*a) _|_ x-ProJ(l*a,b,x)*b by Def2; then (l"*l)*a _|_ x-ProJ(l*a,b,x)*b by VECTSP_1:def 26; then 1_ F*a _|_ x-ProJ(l*a,b,x)*b by A2,VECTSP_1:def 22; then a _|_ x-ProJ(l*a,b,x)*b by VECTSP_1:def 26; then x-ProJ(l*a,b,x)*b _|_ a by Th12; hence thesis by A1,A3,Th24; end; theorem Th32: not b _|_ a & p _|_ a implies ProJ(a,b+p,c) = ProJ(a,b,c) & ProJ(a,b,c+p) = ProJ(a,b,c) proof set 0V = 0.S; assume A1: not b _|_ a & p _|_ a; then not b+p _|_ a by Th14; then A2: c-ProJ(a,b,c)*b _|_ a & c+p-ProJ(a,b,c+p)*b _|_ a & c-ProJ(a,b+p,c)*(b+p) _|_ a by A1,Th27; A3: ProJ(a,b+p,c)*p _|_ a by A1,Def2; A4: -p _|_ a by A1,Th16; c-(ProJ(a,b+p,c)*b+ProJ(a,b+p,c)*p) _|_ a by A2,VECTSP_1:def 26; then c-ProJ(a,b+p,c)*b-ProJ(a,b+p,c)*p _|_ a by VECTSP_1:64; then c-ProJ(a,b+p,c)*b-ProJ(a,b+p,c)*p+ProJ(a,b+p,c)*p _|_ a by A3,Def2; then c+(-ProJ(a,b+p,c)*b)-ProJ(a,b+p,c)*p+ProJ(a,b+p,c)*p _|_ a by RLVECT_1:def 11; then c+(-ProJ(a,b+p,c)*b)+(-ProJ(a,b+p,c)*p)+ProJ(a,b+p,c)*p _|_ a by RLVECT_1:def 11; then c+(-ProJ(a,b+p,c)*b)+((-ProJ(a,b+p,c)*p)+ProJ(a,b+p,c)*p) _|_ a by RLVECT_1:def 6; then c+(-ProJ(a,b+p,c)*b)+0V _|_ a by RLVECT_1:16; then c+(-ProJ(a,b+p,c)*b) _|_ a by RLVECT_1:10; then A5: c-ProJ(a,b+p,c)*b _|_ a by RLVECT_1:def 11; -p+(p+c-ProJ(a,b,c+p)*b) _|_ a by A2,A4,Def2; then -p+(p+c+(-ProJ(a,b,c+p)*b)) _|_ a by RLVECT_1:def 11; then -p+(p+(c+(-ProJ(a,b,c+p)*b))) _|_ a by RLVECT_1:def 6; then (-p+p)+(c+(-ProJ(a,b,c+p)*b)) _|_ a by RLVECT_1:def 6; then 0V+(c+(-ProJ(a,b,c+p)*b)) _|_ a by RLVECT_1:16; then c+(-ProJ(a,b,c+p)*b) _|_ a by RLVECT_1:10; then c-ProJ(a,b,c+p)*b _|_ a by RLVECT_1:def 11; hence thesis by A1,A2,A5,Th24; end; theorem Th33: not b _|_ a & p _|_ b & p _|_ c implies ProJ(a+p,b,c) = ProJ(a,b,c) proof assume A1: not b _|_ a & p _|_ b & p _|_ c; then not a _|_ b by Th12; then not a+p _|_ b by A1,Th14; then A2: not b _|_ a+p by Th12; then A3: c-ProJ(a,b,c)*b _|_ a & c-ProJ(a+p,b,c)*b _|_ a+p by A1,Th27; c _|_ p & b _|_ p by A1,Th12; then c _|_ p & ProJ(a,b,c)*b _|_ p by Def2; then c _|_ p & -(ProJ(a,b,c)*b) _|_ p by Th16; then c+(-(ProJ(a,b,c)*b)) _|_ p by Def2; then c-ProJ(a,b,c)*b _|_ p by RLVECT_1:def 11; then A4: p _|_ c-ProJ(a,b,c)*b by Th12; a _|_ c-ProJ(a,b,c)*b by A3,Th12; then a+p _|_ c-ProJ(a,b,c)*b by A4,Def2; then c-ProJ(a,b,c)*b _|_ a+p by Th12; hence thesis by A2,A3,Th24; end; theorem Th34: not b _|_ a & c-b _|_ a implies ProJ(a,b,c) = 1_ F proof assume A1: not b _|_ a & c-b _|_ a; then A2: c-(1_ F)*b _|_ a by VECTSP_1:def 26; c-ProJ(a,b,c)*b _|_ a by A1,Th27; hence thesis by A1,A2,Th24; end; theorem Th35: not b _|_ a implies ProJ(a,b,b) = 1_ F proof assume A1: not b _|_ a; b+(-b) = 0.S by RLVECT_1:16; then b-b = 0.S by RLVECT_1:def 11; then b-b _|_ a by Th11; hence thesis by A1,Th34; end; theorem Th36: not b _|_ a implies ( x _|_ a iff ProJ(a,b,x) = 0.F ) proof set 0F = 0.F, 0V = 0.S; A1: now assume A2: not b _|_ a & x _|_ a; then A3: x-ProJ(a,b,x)*b _|_ a by Th27; x+0V _|_ a by A2,RLVECT_1:10; then x+(-0V) _|_ a by RLVECT_1:25; then x+(-(0F*b)) _|_ a by VECTSP_1:59; then x-0F*b _|_ a by RLVECT_1:def 11; hence ProJ(a,b,x) = 0.F by A2,A3,Th24; end; now assume not b _|_ a & ProJ(a,b,x) = 0.F; then x-0F*b _|_ a by Th27; then x-0V _|_ a by VECTSP_1:59; then x+(-0V) _|_ a by RLVECT_1:def 11; then x+0V _|_ a by RLVECT_1:25; hence x _|_ a by RLVECT_1:10; end; hence thesis by A1; end; theorem Th37: not b _|_ a & not q _|_ a implies ProJ(a,b,p)*ProJ(a,b,q)" = ProJ(a,q,p) proof assume A1: not b _|_ a & not q _|_ a; then A2: p-ProJ(a,b,p)*b _|_ a & ProJ(a,q,p)*q- ProJ(a,b,ProJ(a,q,p)*q)*b _|_ a & p-ProJ(a,q,p)*q _|_ a by Th27; then (p-ProJ(a,q,p)*q)+(ProJ(a,q,p)*q-ProJ(a,b,ProJ(a,q,p)*q)*b) _|_ a by Def2; then (p+(-ProJ(a,q,p)*q))+(ProJ(a,q,p)*q-(ProJ(a,b,ProJ(a,q,p)*q)*b)) _|_ a by RLVECT_1:def 11; then (p+(-ProJ(a,q,p)*q))+(ProJ(a,q,p)*q+(-(ProJ(a,b,ProJ(a,q,p)*q))*b)) _|_ a by RLVECT_1:def 11; then ((p+(-ProJ(a,q,p)*q))+(ProJ(a,q,p)*q))+(-(ProJ(a,b,ProJ(a,q,p)*q))*b) _|_ a by RLVECT_1:def 6; then (p+((-ProJ(a,q,p)*q)+(ProJ(a,q,p)*q))+(-(ProJ(a,b,ProJ(a,q,p)*q))*b)) _|_ a by RLVECT_1:def 6; then p+0.S+(-(ProJ(a,b,ProJ(a,q,p)*q))*b) _|_ a by RLVECT_1:16; then p+(-(ProJ(a,b,ProJ(a,q,p)*q))*b) _|_ a by RLVECT_1:10; then p-(ProJ(a,b,ProJ(a,q,p)*q)*b) _|_ a by RLVECT_1:def 11; then p-(ProJ(a,q,p)*ProJ(a,b,q))*b _|_ a by A1,Th28; then A3: ProJ(a,q,p)*ProJ(a,b,q) = ProJ(a,b,p) by A1,A2,Th24; A4: ProJ(a,b,q) <> 0.F by A1,Th36; ProJ(a,q,p)*(ProJ(a,b,q)*ProJ(a,b,q)") = ProJ(a,b,p)*ProJ (a,b,q)" by A3,VECTSP_1:def 16; then ProJ(a,q,p)*1_ F = ProJ(a,b,p)*ProJ(a,b,q)" by A4,VECTSP_1:def 22; hence thesis by VECTSP_1:def 19; end; theorem Th38: not b _|_ a & not c _|_ a implies ProJ(a,b,c) = ProJ(a,c,b)" proof set 1F = 1_ F, 0F = 0.F; assume A1: not b _|_ a & not c _|_ a; then ProJ(a,b,b)*ProJ(a,b,c)" = ProJ(a,c,b) by Th37; then ProJ(a,b,c)"*1F = ProJ(a,c,b) by A1,Th35; then A2: ProJ(a,b,c)" = ProJ(a,c,b) by VECTSP_1:def 19; A3: ProJ(a,c,b) <> 0F & ProJ(a,b,c) <> 0F by A1,Th36; then 1F = ProJ(a,c,b)*ProJ(a,b,c) by A2,VECTSP_1:def 22; then ProJ(a,c,b)" = ProJ(a,c,b)"*(ProJ(a,c,b)*ProJ(a,b,c)) by VECTSP_1:def 19 .= (ProJ(a,c,b)"*ProJ(a,c,b))*ProJ(a,b,c) by VECTSP_1:def 16 .= ProJ(a,b,c)*1F by A3,VECTSP_1:def 22; hence thesis by VECTSP_1:def 19; end; theorem Th39: not b _|_ a & b _|_ c+a implies ProJ(a,b,c) = ProJ(c,b,a) proof assume A1: not b _|_ a & b _|_ c+a; then not a _|_ b & c+a _|_ b by Th12; then not c _|_ b by Th13; then A2: not b _|_ c by Th12; c-ProJ(a,b,c)*b _|_ a by A1,Th27; then -ProJ(a,b,c)*b+c _|_ a by RLVECT_1:def 11; then A3: a _|_ -ProJ(a,b,c)*b+c by Th12; ProJ(a,b,c)*b _|_ c+a by A1,Def2; then -ProJ(a,b,c)*b _|_ c+a by Th16; then c _|_ a+(-ProJ(a,b,c)*b) by A3,Def2; then c _|_ a-ProJ(a,b,c)*b by RLVECT_1:def 11; then A4: a-ProJ(a,b,c)*b _|_ c by Th12; a-ProJ(c,b,a)*b _|_ c by A2,Th27; hence thesis by A2,A4,Th24; end; theorem Th40:not a _|_ b & not c _|_ b implies ProJ(c,b,a) = (-ProJ(b,a,c)")*ProJ(a,b,c) proof set 1F = 1_ F; assume A1: not a _|_ b & not c _|_ b; then A2: ProJ(b,a,c) <> 0.F by Th36; then (-1F)*(ProJ(b,a,c)"*ProJ(b,a,c)) = (-1F)*(1F) by VECTSP_1:def 22; then ((-1F)*ProJ(b,a,c)")*ProJ(b,a,c) = (-1F)*(1F) by VECTSP_1:def 16; then ((-1F)*ProJ(b,a,c)")*ProJ(b,a,c) = (-1F) by VECTSP_1:def 19; then (-(ProJ(b,a,c)"*(1F)))*ProJ(b,a,c) = -1F by VECTSP_1:41; then (-ProJ(b,a,c)")*ProJ(b,a,c) = -1F by VECTSP_1:def 19; then ProJ(b,a,(-ProJ(b,a,c)")*c) = -1F by A1,Th28; then (-ProJ(b,a,c)")*c-(-1F)*a _|_ b by A1,Th27; then (-ProJ(b,a,c)")*c-(-a) _|_ b by VECTSP_1:59; then (-ProJ(b,a,c)")*c+(-(-(a))) _|_ b by RLVECT_1:def 11; then (-ProJ(b,a,c)")*c+a _|_ b by RLVECT_1:30; then A3: b _|_ (-ProJ(b,a,c)")*c+a by Th12; A4:not b _|_ a & not b _|_ c by A1,Th12; then A5: ProJ(a,b,(-ProJ(b,a,c)")*c) = ProJ((-ProJ (b,a,c)")*c,b,a) by A3,Th39; -ProJ(b,a,c)" <> 0.F by A2,VECTSP_1:74; then ProJ(a,b,(-ProJ(b,a,c)")*c) = ProJ(c,b,a) by A4,A5,Th31; hence thesis by A4,Th28; end; theorem Th41: (1_ F+1_ F<>0.F) & not a _|_ p & not a _|_ q & not b _|_ p & not b _|_ q implies ProJ(a,p,q)*ProJ(b,q,p) = ProJ(p,a,b)*ProJ(q,b,a) proof assume A1: (1_ F+1_ F<>0.F) & not a _|_ p & not a _|_ q & not b _|_ p & not b _|_ q; A2: now assume A3: not p _|_ q; then A4:not p _|_ a & not q _|_ b & not q _|_ p by A1,Th12; then ProJ(a,p,q) = (-ProJ(p,q,a)")*ProJ(q,p,a) & ProJ(b,q,p) = (-(ProJ(q,p,b)"))*ProJ(p,q,b) by A1,A3,Th40; then ProJ(a,p,q)*ProJ(b,q,p) = ((ProJ(q,p,a)*(-ProJ(p,q,a)"))*(-ProJ(q,p,b)"))*ProJ(p,q,b) by VECTSP_1:def 16 .= (ProJ(q,p,a)*((-ProJ(p,q,a)")*(-ProJ(q,p,b)")))*ProJ (p,q,b) by VECTSP_1:def 16 .= (ProJ(q,p,a)*(ProJ(q,p,b)"*ProJ(p,q,a)"))*ProJ(p,q,b) by VECTSP_1:42 .= ((ProJ(q,p,a)*ProJ(q,p,b)")*ProJ(p,q,a)")*ProJ(p,q,b) by VECTSP_1:def 16 .= (ProJ(q,b,a)*ProJ(p,q,a)")*ProJ(p,q,b) by A1,A3,Th37 .= ProJ(q,b,a)*(ProJ(p,q,b)*ProJ(p,q,a)") by VECTSP_1:def 16 .= ProJ(q,b,a)*ProJ(p,a,b) by A1,A4,Th37; hence thesis; end; A5: now assume A6: not a _|_ b; then A7: not b _|_ a & not p _|_ a & not q _|_ a & not p _|_ b & not q _|_ b by A1,Th12; then ProJ(p,a,b) = (-ProJ(a,b,p)")*ProJ(b,a,p) & ProJ(q,b,a) = (-ProJ(b,a,q)")*ProJ(a,b,q) by A6,Th40; then ProJ(p,a,b)*ProJ(q,b,a) = ((ProJ(b,a,p)*(-ProJ(a,b,p)"))*(-ProJ(b,a,q)"))*ProJ (a,b,q) by VECTSP_1:def 16 .= (ProJ(b,a,p)*((-ProJ(a,b,p)")*(-ProJ(b,a,q)")))*ProJ (a,b,q) by VECTSP_1:def 16 .= (ProJ(b,a,p)*(ProJ(b,a,q)"*ProJ(a,b,p)"))*ProJ(a,b,q) by VECTSP_1:42 .= ((ProJ(b,a,p)*ProJ(b,a,q)")*ProJ(a,b,p)")*ProJ(a,b,q) by VECTSP_1:def 16 .= (ProJ(b,q,p)*ProJ(a,b,p)")*ProJ(a,b,q) by A6,A7,Th37 .= ProJ(b,q,p)*(ProJ(a,b,q)*ProJ(a,b,p)") by VECTSP_1:def 16 .= ProJ(b,q,p)*ProJ(a,p,q) by A7,Th37; hence thesis; end; now assume A8: p _|_ q & a _|_ b; then A9: q _|_ p & b _|_ a & not p _|_ a & not q _|_ a & not p _|_ b & not q _|_ b & a _|_ a by A1,Th12,Th25; then A10: ProJ(a,p,q) = ProJ(a,p+a,q) & ProJ(b,q,p) = ProJ (b,q,p+a) by A8,Th32; A11:not p+a _|_ a by A9,Th14; A12: not p+a _|_ q by A1,A8,Th14; then A13: not a _|_ p+a & not q _|_ p+a & not p+a _|_ q by A11,Th12; then ProJ(a,p+a,q) = (-ProJ(p+a,q,a)")*ProJ(q,p+a,a) & ProJ(b,q,p+a) = (-ProJ(q,p+a,b)")*ProJ(p+a,q,b) by A1,Th40; then ProJ(a,p,q)*ProJ(b,q,p) = ((ProJ(q,p+a,a)*(-ProJ(p+a,q,a)"))*(-ProJ(q,p+a,b)"))*ProJ (p+a,q,b) by A10,VECTSP_1:def 16 .= (ProJ(q,p+a,a)*((-ProJ(p+a,q,a)")*(-ProJ(q,p+a,b)")))*ProJ (p+a,q,b) by VECTSP_1:def 16 .= (ProJ(q,p+a,a)*(ProJ(q,p+a,b)"*ProJ(p+a,q,a)"))*ProJ(p+a,q,b) by VECTSP_1 :42 .= ((ProJ(q,p+a,a)*ProJ(q,p+a,b)")*ProJ(p+a,q,a)")*ProJ (p+a,q,b) by VECTSP_1:def 16 .= (ProJ(q,b,a)*ProJ(p+a,q,a)")*ProJ(p+a,q,b) by A1,A12,Th37 .= ProJ(q,b,a)*(ProJ(p+a,q,b)*ProJ(p+a,q,a)") by VECTSP_1:def 16 .= ProJ(q,b,a)*ProJ(p+a,a,b) by A13,Th37 .= ProJ(q,b,a)*ProJ(p,a,b) by A1,A8,A9,Th33; hence thesis; end; hence thesis by A2,A5; end; theorem Th42: (1_ F+1_ F<>0.F) & not p _|_ a & not p _|_ x & not q _|_ a & not q _|_ x implies ProJ(a,q,p)*ProJ(p,a,x) = ProJ(x,q,p)*ProJ(q,a,x) proof set 0F = 0.F, 1F = 1_ F; assume A1: (1_ F+1_ F<>0.F) & not p _|_ a & not p _|_ x & not q _|_ a & not q _|_ x; then A2: not a _|_ p & not x _|_ p & not a _|_ q & not x _|_ q by Th12; ProJ(p,a,x)*ProJ(q,x,a) = ProJ(a,p,q)*ProJ(x,q,p) by A1,Th41; then A3: ProJ(p,a,x)*ProJ(q,x,a) = ProJ(a,q,p)"*ProJ(x,q,p) by A1,Th38; A4: ProJ(a,q,p) <> 0F by A1,Th36; ProJ(a,q,p)*(ProJ(p,a,x)*ProJ(q,x,a)) = (ProJ(a,q,p)*ProJ(a,q,p)")*ProJ (x,q,p) by A3,VECTSP_1:def 16; then ProJ(a,q,p)*(ProJ(p,a,x)*ProJ(q,x,a)) = ProJ (x,q,p)*(1F) by A4,VECTSP_1:def 22; then ProJ(a,q,p)*(ProJ(p,a,x)*ProJ(q,x,a)) = ProJ(x,q,p) by VECTSP_1:def 19; then (ProJ(a,q,p)*ProJ(p,a,x))*ProJ(q,x,a) = ProJ(x,q,p) by VECTSP_1:def 16; then A5: (ProJ(a,q,p)*ProJ(p,a,x))*ProJ(q,a,x)" = ProJ(x,q,p) by A2,Th38; A6: ProJ(q,a,x) <> 0F by A2,Th36; (ProJ(a,q,p)*ProJ(p,a,x))*(ProJ(q,a,x)"*ProJ(q,a,x)) = ProJ(x,q,p)*ProJ (q,a,x) by A5,VECTSP_1:def 16; then (ProJ(a,q,p)*ProJ(p,a,x))*(1F) = ProJ(x,q,p)*ProJ (q,a,x) by A6,VECTSP_1:def 22; hence thesis by VECTSP_1:def 19; end; theorem Th43: (1_ F+1_ F<>0.F) & not p _|_ a & not p _|_ x & not q _|_ a & not q _|_ x & not b _|_ a implies ProJ(a,b,p)*ProJ(p,a,x)*ProJ(x,p,y) = ProJ(a,b,q)*ProJ(q,a,x)*ProJ(x,q,y) proof set 0F = 0.F, 1F = 1_ F; assume A1: (1_ F+1_ F<>0.F) & not p _|_ a & not p _|_ x & not q _|_ a & not q _|_ x & not b _|_ a; A2: now assume y _|_ x; then ProJ(x,p,y) = 0F & ProJ(x,q,y) = 0F by A1,Th36; then ProJ(a,b,p)*ProJ(p,a,x)*ProJ(x,p,y) = 0F & ProJ(a,b,q)*ProJ(q,a,x)*ProJ(x,q,y) = 0F by VECTSP_1:39; hence thesis; end; now assume A3: not y _|_ x; ProJ(a,q,p)*ProJ(p,a,x) = ProJ(x,q,p)*ProJ(q,a,x) by A1,Th42; then (ProJ(a,b,p)*ProJ(a,b,q)")*ProJ(p,a,x) = ProJ(x,q,p)*ProJ (q,a,x) by A1,Th37; then (ProJ(a,b,q)"*ProJ(a,b,p))*ProJ(p,a,x) = (ProJ(x,y,p)*ProJ(x,y,q)")*ProJ (q,a,x) by A1,A3,Th37; then ProJ(a,b,q)*(ProJ(a,b,q)"*(ProJ(a,b,p)*ProJ(p,a,x))) = ProJ(a,b,q)*((ProJ(x,y,p)*ProJ(x,y,q)")*ProJ (q,a,x)) by VECTSP_1:def 16; then A4: (ProJ(a,b,q)*ProJ(a,b,q)")*(ProJ(a,b,p)*ProJ(p,a,x)) = ProJ(a,b,q)*((ProJ(x,y,p)*ProJ(x,y,q)")*ProJ (q,a,x)) by VECTSP_1:def 16; ProJ(a,b,q) <> 0F by A1,Th36; then (ProJ(a,b,p)*ProJ(p,a,x))*(1F) = ProJ(a,b,q)*((ProJ(x,y,p)*ProJ(x,y,q)")*ProJ (q,a,x)) by A4,VECTSP_1:def 22; then ProJ(a,b,p)*ProJ(p,a,x) = ProJ(a,b,q)*((ProJ(x,y,p)*ProJ(x,y,q)")*ProJ (q,a,x)) by VECTSP_1:def 19 ; then ProJ(a,b,p)*ProJ(p,a,x) = ProJ(a,b,q)*((ProJ(x,y,q)"*ProJ(x,p,y)")*ProJ (q,a,x)) by A1,A3,Th38; then ProJ(a,b,p)*ProJ(p,a,x) = (ProJ(a,b,q)*(ProJ(x,y,q)"*ProJ(x,p,y)"))*ProJ (q,a,x) by VECTSP_1:def 16; then ProJ(a,b,p)*ProJ(p,a,x) = ProJ(q,a,x)*((ProJ(a,b,q)*ProJ(x,y,q)")*ProJ (x,p,y)") by VECTSP_1:def 16 ; then ProJ(a,b,p)*ProJ(p,a,x)*ProJ(x,p,y) = ((ProJ(q,a,x)*(ProJ(a,b,q)*ProJ(x,y,q)"))*ProJ(x,p,y)")*ProJ (x,p,y) by VECTSP_1:def 16; then A5: ProJ(a,b,p)*ProJ(p,a,x)*ProJ(x,p,y) = (ProJ(q,a,x)*(ProJ(a,b,q)*ProJ(x,y,q)"))*(ProJ(x,p,y)"*ProJ (x,p,y)) by VECTSP_1:def 16; ProJ(x,p,y) <> 0F by A1,A3,Th36; then ProJ(a,b,p)*ProJ(p,a,x)*ProJ(x,p,y) = (ProJ(q,a,x)*(ProJ(a,b,q)*ProJ(x,y,q)"))*(1F) by A5,VECTSP_1:def 22; then ProJ(a,b,p)*ProJ(p,a,x)*ProJ(x,p,y) = ProJ(q,a,x)*(ProJ(a,b,q)*ProJ(x,y,q)") by VECTSP_1:def 19; then ProJ(a,b,p)*ProJ(p,a,x)*ProJ(x,p,y) = ProJ(q,a,x)*(ProJ(a,b,q)*ProJ(x,q,y)) by A1,A3,Th38; hence thesis by VECTSP_1:def 16; end; hence thesis by A2; end; theorem Th44: not a _|_ p & not x _|_ p & not y _|_ p implies ProJ(p,a,x)*ProJ(x,p,y) = (-ProJ(p,a,y))*ProJ(y,p,x) proof set 0F = 0.F, 1F = 1_ F; assume A1: not a _|_ p & not x _|_ p & not y _|_ p; then A2: not a _|_ p & not x _|_ p & not y _|_ p & not p _|_ a & not p _|_ x & not p _|_ y by Th12; A3: now assume y _|_ x; then y _|_ x & x _|_ y by Th12; then ProJ(x,p,y) = 0F & ProJ(y,p,x) = 0F by A2,Th36; then ProJ(p,a,x)*ProJ(x,p,y) = 0F & (-ProJ(p,a,y))*ProJ (y,p,x) = 0F by VECTSP_1:39; hence thesis; end; now assume A4: not y _|_ x; then A5: not y _|_ x & not x _|_ y by Th12; ProJ(p,a,y)*ProJ(p,a,x)" = ProJ(p,x,y) by A1,Th37; then (ProJ(p,a,y)*ProJ(p,a,x)")*ProJ(p,a,x) = ((-ProJ(x,y,p)")*ProJ(y,x,p))*ProJ(p,a,x) by A2,A4,Th40; then A6: ProJ(p,a,y)*(ProJ(p,a,x)"*ProJ(p,a,x)) = ((-ProJ(x,y,p)")*ProJ(y,x,p))*ProJ(p,a,x) by VECTSP_1:def 16; ProJ(p,a,x) <> 0F by A1,Th36; then ProJ(p,a,y)*(1F) = ((-ProJ(x,y,p)")*ProJ(y,x,p))*ProJ(p,a,x) by A6,VECTSP_1:def 22; then ProJ(p,a,y) = (ProJ(y,x,p)*(-ProJ(x,y,p)"))*ProJ (p,a,x) by VECTSP_1:def 19; then ProJ(p,a,y) = ProJ(y,x,p)*((-ProJ(x,y,p)")*ProJ (p,a,x)) by VECTSP_1:def 16; then ProJ(y,p,x)*ProJ(p,a,y) = ProJ(y,p,x)*(ProJ(y,p,x)"*((-ProJ(x,y,p)")*ProJ(p,a,x))) by A2,A5,Th38; then A7: ProJ(y,p,x)*ProJ(p,a,y) = (ProJ(y,p,x)*ProJ(y,p,x)")*((-ProJ(x,y,p)")*ProJ (p,a,x)) by VECTSP_1:def 16; ProJ(y,p,x) <> 0F by A2,A5,Th36; then ProJ(y,p,x)*ProJ(p,a,y) = ((-ProJ(x,y,p)")*ProJ(p,a,x))*(1F) by A7,VECTSP_1:def 22; then ProJ(p,a,y)*ProJ(y,p,x) = (-ProJ(x,y,p)")*ProJ(p,a,x) by VECTSP_1:def 19; then -(ProJ(p,a,y)*ProJ(y,p,x)) = -(-ProJ(x,y,p)"*ProJ (p,a,x)) by VECTSP_1:41; then -(ProJ(p,a,y)*ProJ(y,p,x)) = ProJ(x,y,p)"*ProJ(p,a,x) by RLVECT_1:30; then (-ProJ(p,a,y))*ProJ(y,p,x) = ProJ(x,y,p)"*ProJ(p,a,x) by VECTSP_1:41; hence thesis by A2,A4,Th38; end; hence thesis by A3; end; :: :: 6. BILINEAR ANTISYMMETRIC FORM :: definition let F,S,x,y,a,b; assume that A1: not b _|_ a and A2: 1_ F+1_ F<>0.F; func PProJ(a,b,x,y) -> Element of F means :Def7: for q st not q _|_ a & not q _|_ x holds it = ProJ(a,b,q)* ProJ(q,a,x)*ProJ(x,q,y) if ex p st (not p _|_ a & not p _|_ x) , it = 0.F if for p holds p _|_ a or p _|_ x; existence proof thus (ex p st not p _|_ a & not p _|_ x) implies ex IT being Element of F st for q st not q _|_ a & not q _|_ x holds IT = ProJ(a,b,q)*ProJ(q,a,x)*ProJ (x,q,y) proof given p such that A3: not p _|_ a & not p _|_ x; take ProJ(a,b,p)*ProJ(p,a,x)*ProJ(x,p,y); let q; assume not q _|_ a & not q _|_ x; hence ProJ(a,b,p)*ProJ(p,a,x)*ProJ(x,p,y) = ProJ(a,b,q)*ProJ(q,a,x)*ProJ (x,q,y) by A1,A2,A3,Th43; end; thus thesis; end; uniqueness proof let IT1,IT2 be Element of F; thus (ex p st not p _|_ a & not p _|_ x) & (for q st not q _|_ a & not q _|_ x holds IT1 = ProJ(a,b,q)* ProJ(q,a,x)*ProJ(x,q,y)) & (for q st not q _|_ a & not q _|_ x holds IT2 = ProJ(a,b,q)*ProJ(q,a,x)*ProJ (x,q,y)) implies IT1 = IT2 proof given p such that A4: not p _|_ a & not p _|_ x; assume that A5: for q st not q _|_ a & not q _|_ x holds IT1 = ProJ(a,b,q)*ProJ(q,a,x)*ProJ(x,q,y) and A6: for q st not q _|_ a & not q _|_ x holds IT2 = ProJ(a,b,q)*ProJ(q,a,x)*ProJ(x,q,y); consider r such that A7: not r _|_ a & not r _|_ x by A4; IT1 = ProJ(a,b,r)*ProJ(r,a,x)*ProJ(x,r,y) by A5,A7; hence thesis by A6,A7; end; thus thesis; end; consistency; end; canceled 2; theorem Th47: (1_ F+1_ F<>0.F) & not b _|_ a & x=0.S implies PProJ(a,b,x,y) = 0.F proof assume that A1: (1_ F+1_ F<>0.F) and A2: not b _|_ a & x=0.S; for p holds p _|_ a or p _|_ x proof let p be Element of S; x _|_ p by A2,Th11; hence thesis by Th12; end; hence thesis by A1,A2,Def7; end; Lm6: x _|_ 0.S proof 0.S _|_ x by Th11; hence thesis by Th12; end; theorem Th48: (1_ F+1_ F<>0.F) & not b _|_ a implies (PProJ(a,b,x,y) = 0.F iff y _|_ x) proof set 0F = 0.F; assume that A1: (1_ F+1_ F<>0.F) and A2: not b _|_ a; A3: a<>0.S by A2,Lm6; A4: PProJ(a,b,x,y) = 0.F implies y _|_ x proof assume A5: PProJ(a,b,x,y) = 0.F; A6: now assume for p holds p _|_ a or p _|_ x; then x = 0.S by A3,Th21; hence thesis by Lm6; end; now given p such that A7: not p _|_ a & not p _|_ x; ProJ(a,b,p)*ProJ(p,a,x)*ProJ(x,p,y) = 0F by A1,A2,A5,A7,Def7; then ProJ(a,b,p)*ProJ(p,a,x) = 0F or ProJ(x,p,y) = 0F by VECTSP_1:44; then A8: ProJ(a,b,p) = 0.F or ProJ(p,a,x) = 0.F or ProJ(x,p,y) = 0.F by VECTSP_1:44; now assume A9: ProJ(p,a,x) = 0.F; not a _|_ p by A7,Th12; then x _|_ p by A9,Th36; hence contradiction by A7,Th12; end; hence thesis by A2,A7,A8,Th36; end; hence thesis by A6; end; y _|_ x implies PProJ(a,b,x,y) = 0.F proof assume A10: y _|_ x; A11: now assume x = 0.S; then for p holds p _|_ a or p _|_ x by Lm6; hence thesis by A1,A2,Def7; end; now assume x<>0.S; then consider p such that A12: not p _|_ a & not p _|_ x by A3,Th21; ProJ(x,p,y) = 0F by A10,A12,Th36; then ProJ(a,b,p)*ProJ(p,a,x)*ProJ(x,p,y) = 0.F by VECTSP_1:39; hence thesis by A1,A2,A12,Def7; end; hence thesis by A11; end; hence thesis by A4; end; theorem (1_ F+1_ F<>0.F) & not b _|_ a implies PProJ(a,b,x,y) = -PProJ(a,b,y,x) proof set 0F = 0.F, 1F = 1_ F; assume A1: (1_ F+1_ F<>0.F) & not b _|_ a; A2: now assume x _|_ y; then y _|_ x & x _|_ y by Th12; then PProJ(a,b,x,y) = 0F & (-1F)*PProJ(a,b,y,x) = (-1F)*0F by A1,Th48; then PProJ(a,b,x,y) = 0F & -(PProJ (a,b,y,x)*(1F)) = (-1F)*0F by VECTSP_1:41; then PProJ(a,b,x,y) = 0F & -PProJ(a,b,y,x) = (-1F)*0F by VECTSP_1:def 19; hence thesis by VECTSP_1:39; end; now assume not x _|_ y; then x <> 0.S & y <> 0.S & a <> 0.S by A1,Lm6,Th11; then consider r such that A3: not r _|_ a & not r _|_ x & not r _|_ y by A1,Th22; A4: not a _|_ b & not a _|_ r & not x _|_ r & not y _|_ r by A1,A3,Th12; A5: PProJ(a,b,x,y) = ProJ(a,b,r)*ProJ(r,a,x)*ProJ(x,r,y) by A1,A3,Def7; PProJ(a,b,y,x) = ProJ(a,b,r)*ProJ(r,a,y)*ProJ(y,r,x) by A1,A3,Def7; then PProJ(a,b,y,x) = ProJ(a,b,r)*(ProJ(r,a,y)*ProJ (y,r,x)) by VECTSP_1:def 16; then PProJ(a,b,y,x) = ProJ(a,b,r)*((-(ProJ(r,a,x)))*ProJ (x,r,y)) by A4,Th44; then PProJ(a,b,y,x) = ((-(ProJ(r,a,x)))*ProJ(a,b,r))*ProJ (x,r,y) by VECTSP_1:def 16; then PProJ(a,b,y,x) = (-ProJ(r,a,x)*ProJ(a,b,r))*ProJ (x,r,y) by VECTSP_1:41; then (-1F)*PProJ(a,b,y,x) = (-1F)*(-ProJ(a,b,r)*ProJ(r,a,x)*ProJ (x,r,y)) by VECTSP_1:41; then -(PProJ(a,b,y,x)*(1F)) = (-1F)*(-ProJ(a,b,r)*ProJ(r,a,x)*ProJ (x,r,y)) by VECTSP_1:41; then -PProJ(a,b,y,x) = (-1F)*(-ProJ(a,b,r)*ProJ(r,a,x)*ProJ (x,r,y)) by VECTSP_1:def 19; then -PProJ(a,b,y,x) = (ProJ(a,b,r)*ProJ(r,a,x)*ProJ (x,r,y))*(1F) by VECTSP_1:42; hence thesis by A5,VECTSP_1:def 19; end; hence thesis by A2; end; theorem (1_ F+1_ F<>0.F) & not b _|_ a implies PProJ(a,b,x,l*y) = l*PProJ(a,b,x,y) proof set 0F = 0.F; assume that A1: (1_ F+1_ F<>0.F) and A2: not b _|_ a; A3: now assume A4: x _|_ y; then y _|_ x by Th12; then l*y _|_ x by Def2; then x _|_ y & y _|_ x & l*y _|_ x & x _|_ l*y by A4,Th12; then l*PProJ(a,b,x,y) = l*0F & PProJ(a,b,x,l*y) = 0F by A1,A2,Th48; hence thesis by VECTSP_1:39; end; now assume not x _|_ y; then a <> 0.S & x <> 0.S by A2,Lm6,Th11; then consider p such that A5: not p _|_ a & not p _|_ x by Th21; A6: PProJ(a,b,x,l*y) = ProJ(a,b,p)*ProJ(p,a,x)*ProJ (x,p,l*y) by A1,A2,A5,Def7; A7: PProJ(a,b,x,y) = ProJ(a,b,p)*ProJ(p,a,x)*ProJ(x,p,y) by A1,A2,A5,Def7; PProJ(a,b,x,l*y) = (l*ProJ(x,p,y))*(ProJ(a,b,p)*ProJ(p,a,x)) by A5,A6, Th28 ; hence thesis by A7,VECTSP_1:def 16; end; hence thesis by A3; end; theorem (1_ F+1_ F<>0.F) & not b _|_ a implies PProJ(a,b,x,y+z) = PProJ(a,b,x,y) + PProJ (a,b,x,z) proof assume that A1: (1_ F+1_ F<>0.F) and A2: not b _|_ a; set 0F = 0.F; A3: now assume x = 0.S; then PProJ(a,b,x,y+z) = 0F & PProJ(a,b,x,y) = 0F & PProJ (a,b,x,z) = 0F by A1,A2,Th47; hence thesis by RLVECT_1:10; end; now assume x <> 0.S; then a <> 0.S & x <> 0.S by A2,Lm6; then consider p such that A4: not p _|_ a & not p _|_ x by Th21; A5: PProJ(a,b,x,y+z) = ProJ(a,b,p)*ProJ(p,a,x)*ProJ (x,p,y+z) by A1,A2,A4,Def7; A6: PProJ(a,b,x,y) = ProJ(a,b,p)*ProJ(p,a,x)*ProJ(x,p,y) by A1,A2,A4,Def7; A7: PProJ(a,b,x,z) = ProJ(a,b,p)*ProJ(p,a,x)*ProJ(x,p,z) by A1,A2,A4,Def7; ProJ(x,p,y+z) = ProJ(x,p,y) + ProJ(x,p,z) by A4,Th29; hence thesis by A5,A6,A7,VECTSP_1:def 18; end; hence thesis by A3; end;