The Mizar article:

Finite Sums of Vectors in Vector Space

by
Wojciech A. Trybulec

Received July 12, 1990

Copyright (c) 1990 Association of Mizar Users

MML identifier: VECTSP_3
[ MML identifier index ]


environ

 vocabulary RLVECT_1, FINSEQ_1, RELAT_1, FUNCT_1, FINSEQ_4, BINOP_1, VECTSP_1,
      LATTICES, ARYTM_1;
 notation TARSKI, XREAL_0, FINSEQ_1, RELAT_1, FUNCT_1, STRUCT_0, RLVECT_1,
      VECTSP_1, FINSEQ_4, NAT_1;
 constructors VECTSP_1, FINSEQ_4, NAT_1, XREAL_0, MEMBERED, XBOOLE_0;
 clusters VECTSP_1, RELSET_1, STRUCT_0, ARYTM_3, MEMBERED, ZFMISC_1, XBOOLE_0;
 requirements NUMERALS, SUBSET, BOOLE;
 definitions TARSKI;
 theorems FINSEQ_1, FINSEQ_2, FINSEQ_3, FINSEQ_4, FUNCT_1, NAT_1, RLVECT_1,
      RLVECT_2, VECTSP_1;
 schemes FINSEQ_1, NAT_1;

begin

reserve x,y for set,
        k,n for Nat;

canceled 8;

theorem Th9:
 for R being add-associative right_zeroed right_complementable Abelian
   associative left_unital distributive (non empty doubleLoopStr),
     a being Element of R
 for V being Abelian add-associative right_zeroed
         right_complementable VectSp-like (non empty VectSpStr over R),
     F,G being FinSequence of the carrier of V
  st len F = len G &
     for k for v being Element of V
       st k in dom F & v = G.k holds F.k = a * v
   holds Sum(F) = a * Sum(G)
    proof let R be add-associative right_zeroed right_complementable Abelian
            associative left_unital distributive (non empty doubleLoopStr),
              a be Element of R;
     let V be Abelian add-associative right_zeroed
         right_complementable VectSp-like (non empty VectSpStr over R),
         F,G be FinSequence of the carrier of V;
     defpred P[Nat] means
         for H,I being FinSequence of the carrier of V
        st len H = len I & len H = $1 &
          (for k for v be Element of V
           st k in dom H & v = I.k holds H.k = a * v) holds
            Sum(H) = a * Sum(I);
     A1: P[0] proof let H,I be FinSequence of the carrier of V;
       assume that A2: len H = len I & len H = 0 and
                        for k for v being Element of V
                       st k in dom H & v = I.k holds H.k = a * v;
          H = <*>(the carrier of V) &
        I = <*>(the carrier of V) by A2,FINSEQ_1:32;
        then Sum(H) = 0.V & Sum(I) = 0.V by RLVECT_1:60;
      hence Sum(H) = a * Sum(I) by VECTSP_1:59;
     end;
      A3: P[n] implies P[n+1]
       proof
        assume A4: for H,I being FinSequence of the carrier of V
         st len H = len I & len H = n &
          for k for v being Element of V
           st k in dom H & v = I.k holds H.k = a * v holds
                    Sum(H) = a * Sum(I);
       let H,I be FinSequence of the carrier of V;
        assume that A5: len H = len I and A6: len H = n + 1 and
                    A7: for k for v being Element of V
                     st k in dom H & v = I.k holds H.k = a * v;
         reconsider p = H | (Seg n),q = I | (Seg n)
           as FinSequence of the carrier of V by FINSEQ_1:23;
A8:          n <= n + 1 by NAT_1:37;
          then A9: len p = n & len q = n by A5,A6,FINSEQ_1:21;
A10:          now let k; let v be Element of V;
            assume that A11: k in dom p and A12: v = q.k;
A13:           dom p c= dom H by A6,A8,A9,FINSEQ_3:32;
               dom q = dom p by A9,FINSEQ_3:31;
             then I.k = q.k by A11,FUNCT_1:70;
             then H.k = a * v by A7,A11,A12,A13;
           hence p.k = a * v by A11,FUNCT_1:70;
          end;
             n + 1 in Seg(n + 1) by FINSEQ_1:6;
then A14:       n + 1 in dom H & dom H = dom I by A5,A6,FINSEQ_1:def 3,FINSEQ_3
:31;
         then reconsider v1 = H.(n + 1),v2 = I.(n + 1)
          as Element of V by FINSEQ_2:13;
          A15: v1 = a * v2 by A7,A14;
A16:       p = H | (dom p) & q = I | (dom q) by A5,A6,A8,FINSEQ_1:21;
       hence Sum(H) = Sum(p) + v1 by A6,A9,RLVECT_1:55
                .= a * Sum(q) + a * v2 by A4,A9,A10,A15
                .= a * (Sum(q) + v2) by VECTSP_1:def 26
                .= a * Sum(I) by A5,A6,A9,A16,RLVECT_1:55;
      end;
         for n holds P[n] from Ind(A1,A3);
     hence thesis;
    end;

theorem
   for R being add-associative right_zeroed right_complementable Abelian
   associative left_unital distributive (non empty doubleLoopStr),
     a being Element of R
 for V being Abelian add-associative right_zeroed
         right_complementable VectSp-like (non empty VectSpStr over R),
     F,G being FinSequence of the carrier of V
  st len F = len G & for k st k in dom F holds G.k = a * F/.k
  holds Sum(G) = a * Sum(F)
 proof
  let R be add-associative right_zeroed right_complementable Abelian
    associative left_unital distributive (non empty doubleLoopStr),
      a be Element of R;
  let V be Abelian add-associative right_zeroed
         right_complementable VectSp-like (non empty VectSpStr over R),
     F,G be FinSequence of the carrier of V;
  assume that A1: len F = len G and
                   A2: for k st k in dom F holds G.k = a * F/.k;
     now let k; let v be Element of V;
     assume that A3: k in dom G and A4: v = F.k;
A5:   k in dom F by A1,A3,FINSEQ_3:31;
      then v = F/.k by A4,FINSEQ_4:def 4;
    hence G.k = a * v by A2,A5;
   end;
  hence thesis by A1,Th9;
 end;

canceled 2;

theorem
   for R being add-associative right_zeroed right_complementable Abelian
   associative left_unital distributive (non empty doubleLoopStr)
 for V being Abelian add-associative right_zeroed
         right_complementable (non empty VectSpStr over R),
     F,G,H being FinSequence of the carrier of V
  st len F = len G & len F = len H &
     for k st k in dom F holds H.k = F/.k - G/.k
  holds Sum(H) = Sum(F) - Sum(G)
proof
  let R be add-associative right_zeroed right_complementable Abelian
    associative left_unital distributive (non empty doubleLoopStr);
  let V be Abelian add-associative right_zeroed
         right_complementable (non empty VectSpStr over R),
     F,G,H be FinSequence of the carrier of V;
  assume that A1: len F = len G & len F = len H and
                   A2: for k st k in dom F holds H.k = F/.k - G/.k;
   deffunc F(Nat) = - G/.$1;
   consider I being FinSequence such that A3: len I = len G and
    A4: for k st k in Seg(len G) holds I.k = F(k) from SeqLambda;
A5: Seg len G = dom G by FINSEQ_1:def 3;
      rng I c= the carrier of V
     proof let x;
       assume x in rng I;
        then consider y such that A6: y in dom I & I.y = x by FUNCT_1:def 5;
        reconsider y as Nat by A6,FINSEQ_3:25;
           y in Seg(len G) by A3,A6,FINSEQ_1:def 3;
         then x = - G/.y by A4,A6;
        then reconsider v = x as Element of V;
           v in V by RLVECT_1:3;
      hence thesis;
     end;
   then reconsider I as FinSequence of the carrier of V by FINSEQ_1:def 4;
    A7: Sum(I) = - Sum(G) by A3,A4,A5,RLVECT_2:6;
      now let k;
      assume A8: k in dom F;
       then k in dom I by A1,A3,FINSEQ_3:31;
       then A9: I.k = I/.k by FINSEQ_4:def 4;
A10:    dom F = dom G by A1,FINSEQ_3:31;
     thus H.k = F/.k - G/.k by A2,A8
             .= F/.k + - G/.k by RLVECT_1:def 11
             .= F/.k + I/.k by A4,A5,A8,A9,A10;
    end;
    then Sum(H) = Sum(F) + Sum(I) by A1,A3,RLVECT_2:4;
  hence thesis by A7,RLVECT_1:def 11;
 end;

canceled 7;

theorem
   for R being add-associative right_zeroed right_complementable Abelian
   associative left_unital distributive (non empty doubleLoopStr),
     a being Element of R
 for V being Abelian add-associative right_zeroed
         right_complementable VectSp-like (non empty VectSpStr over R)
 holds a * Sum(<*>(the carrier of V)) = 0.V
  proof
  let R be add-associative right_zeroed right_complementable Abelian
    associative left_unital distributive (non empty doubleLoopStr),
      a be Element of R;
  let V be Abelian add-associative right_zeroed
         right_complementable VectSp-like (non empty VectSpStr over R);
   thus a * Sum(<*>(the carrier of V)) = a * 0.V by RLVECT_1:60
                                    .= 0.V by VECTSP_1:59;
  end;

canceled;

theorem
   for R being add-associative right_zeroed right_complementable Abelian
   associative left_unital distributive (non empty doubleLoopStr),
     a being Element of R
 for V being Abelian add-associative right_zeroed
         right_complementable VectSp-like (non empty VectSpStr over R),
     v,u being Element of V
 holds a * Sum<* v,u *> = a * v + a * u
  proof
  let R be add-associative right_zeroed right_complementable Abelian
    associative left_unital distributive (non empty doubleLoopStr),
      a be Element of R;
  let V be Abelian add-associative right_zeroed
         right_complementable VectSp-like (non empty VectSpStr over R),
      v,u be Element of V;
   thus a * Sum<* v,u *> = a * (v + u) by RLVECT_1:62
                      .= a * v + a * u by VECTSP_1:def 26;
  end;

theorem
   for R being add-associative right_zeroed right_complementable Abelian
   associative left_unital distributive (non empty doubleLoopStr),
     a being Element of R
 for V being Abelian add-associative right_zeroed
         right_complementable VectSp-like (non empty VectSpStr over R),
     v,u,w being Element of V
 holds a * Sum<* v,u,w *> = a * v + a * u + a * w
  proof
  let R be add-associative right_zeroed right_complementable Abelian
    associative left_unital distributive (non empty doubleLoopStr),
      a be Element of R;
  let V be Abelian add-associative right_zeroed
         right_complementable VectSp-like (non empty VectSpStr over R),
      v,u,w be Element of V;
   thus a * Sum<* v,u,w *> = a * (v + u + w) by RLVECT_1:63
                        .= a * (v + u) + a * w by VECTSP_1:def 26
                        .= a * v + a * u + a * w by VECTSP_1:def 26;
  end;

theorem
   for V being Abelian add-associative right_zeroed
         right_complementable (non empty LoopStr)
 holds - Sum(<*>(the carrier of V)) = 0.V
  proof
  let V be Abelian add-associative right_zeroed
         right_complementable (non empty LoopStr);
   thus - Sum(<*>(the carrier of V)) = - 0.V by RLVECT_1:60
                                    .= 0.V by RLVECT_1:25;
  end;

canceled;

theorem
   for V being Abelian add-associative right_zeroed
         right_complementable (non empty LoopStr),
     v,u being Element of V
 holds - Sum<* v,u *> = (- v) - u
  proof
  let V be Abelian add-associative right_zeroed
         right_complementable (non empty LoopStr),
      v,u be Element of V;
   thus - Sum<* v,u *> = - (v + u) by RLVECT_1:62
                    .= (- v) - u by VECTSP_1:64;
  end;

theorem
   for V being Abelian add-associative right_zeroed
         right_complementable (non empty LoopStr),
     v,u,w being Element of V
 holds - Sum<* v,u,w *> = ((- v) - u) - w
  proof
  let V be Abelian add-associative right_zeroed
         right_complementable (non empty LoopStr),
      v,u,w be Element of V;
   thus - Sum<* v,u,w *> = - (v + u + w) by RLVECT_1:63
                      .= (- (v + u)) - w by VECTSP_1:64
                      .= ((- v) - u) - w by VECTSP_1:64;
  end;

canceled 4;

theorem
   for V being Abelian add-associative right_zeroed
         right_complementable (non empty LoopStr),
     v being Element of V
 holds Sum<* v,- v *> = 0.V & Sum<* - v,v *> = 0.V
  proof
  let V be Abelian add-associative right_zeroed
         right_complementable (non empty LoopStr),
      v be Element of V;
   thus Sum<* v,- v *> = v + (- v) by RLVECT_1:62
                    .= 0.V by VECTSP_1:66;
   hence thesis by RLVECT_1:72;
  end;

theorem
   for V being Abelian add-associative right_zeroed
         right_complementable (non empty LoopStr),
     v,w being Element of V
 holds Sum<* v,- w *> = v - w & Sum<* - w,v *> = v - w
  proof
  let V be Abelian add-associative right_zeroed
         right_complementable (non empty LoopStr),
      v,w be Element of V;
   thus Sum<* v,- w *> = v + (- w) by RLVECT_1:62
                    .= v - w by RLVECT_1:def 11;
   hence thesis by RLVECT_1:72;
  end;

theorem
   for V being Abelian add-associative right_zeroed
         right_complementable (non empty LoopStr),
     v,w being Element of V
 holds Sum<* - v,- w *> = - (v + w) & Sum<* - w,- v *> = - (v + w)
  proof
  let V be Abelian add-associative right_zeroed
         right_complementable (non empty LoopStr),
      v,w be Element of V;
   thus Sum<* - v,- w *> = (- v) + (- w) by RLVECT_1:62
                      .= - (v + w) by RLVECT_1:45;
   hence thesis by RLVECT_1:72;
  end;



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