theorem Th24:
  for K being unital associative non empty multMagma, a being
  Element of K, n being Nat holds a|^(n+1) = (a|^n) * a
proof
  let K be unital associative non empty multMagma, a be
  Element of K, n be Nat;
  a|^(n+1) = (a|^n) * (a|^1) by BINOM:10 .= (a|^n) * a by BINOM:8;
  hence thesis;
end;
