
theorem poly2a:
for L being left_unital non empty doubleLoopStr,
    p being sequence of L
holds 1.L * p = p
proof
let L be left_unital non empty doubleLoopStr,
    p be sequence of L;
set t = 1.L * p;
now let x be object;
  assume x in NAT;
  then reconsider i = x as Element of NAT;
  thus t.x = 1.L * (p.i) by POLYNOM5:def 4 .= p.x;
  end;
hence thesis by FUNCT_2:12;
end;
