reserve s for set,
  i,j for Nat,
  c,c1,c2,c3 for Complex,
  F,F1,F2 for complex-valued FinSequence,
  R,R1,R2 for i-element complex-valued FinSequence;

theorem
  R1 - R2 = i|->0c implies R1 = R2
proof
A1: R1 is i-element FinSequence of COMPLEX &
   R2 is i-element FinSequence of COMPLEX by FINSEQ_1:102;
  assume R1 - R2 = i|->0c; then
  R1 = --R2 by A1,BINOP_2:1,FINSEQOP:74,SEQ_4:51,52;
  hence thesis;
end;
