reserve x,y,z,x1,x2,y1,y2,z1,z2 for object,
  i,j,k,l,n,m for Nat,
  D for non empty set,
  K for Ring;
reserve a for Element of K;

theorem
  for L be add-associative right_zeroed right_complementable non empty
  addLoopStr for p be FinSequence of L st for i be Element of NAT st
  i in dom p holds p.i = 0.L holds Sum p = 0.L
  by Lm1;
