reserve T, X, Y for Subset of MC-wff;
reserve p, q, r, s for Element of MC-wff;

theorem
  T is IPC_theory implies IPC-Taut c= T
proof
  assume
A1: T is IPC_theory;
  IPC-Taut c= CnIPC(T) by Th13,XBOOLE_1:2;
  hence thesis by A1,Th15;
end;
