reserve i,j,k for Nat;
reserve K for non empty addLoopStr,
  a for Element of K,
  p for FinSequence of the carrier of K,
  R for Element of i-tuples_on the carrier of K;

theorem
  -<*a*> = <*-a*>
proof
  thus -<*a*> = <*(comp K).a*> by FINSEQ_2:35
    .= <*-a*> by VECTSP_1:def 13;
end;
