reserve x for set;
reserve a, b, c, d, e for Real;
reserve m, n, m1, m2 for Nat;
reserve k, l for Integer;
reserve p for Rational;

theorem
  a to_power 1 = a
proof
  thus a to_power 1 = a #Z 1 by Def2
    .= a by PREPOWER:35;
end;
