reserve i,j,k for Nat;

theorem
  for K being non empty addLoopStr, p1, p2 be FinSequence of the carrier
  of K, a1, a2 being Element of K, i being Nat st i in dom (p1+p2) &
  a1 = p1.i & a2 = p2.i holds (p1+p2).i = a1 + a2 by FUNCOP_1:22;
