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
  2 to_power 6 = 64
proof
  thus 2 to_power 6 = 2 to_power (3+3) .= 2 to_power 3 * 2 to_power 3 by Th27
    .= 64 by Th61;
end;
