
theorem Th2:
  for a being Real, b,c being Integer st a <> 0 holds
    a to_power (b+c) = a to_power b * a to_power c
  proof
    let a be Real;
    let b,c be Integer;
    assume A1: a <> 0;
    thus a to_power b * a to_power c = a #Z b * a to_power c by POWER:43
    .= a #Z b * a #Z c by POWER:43
    .= a #Z (b+c) by A1,PREPOWER:44
    .= a to_power (b+c) by POWER:43;
  end;
