reserve A for QC-alphabet;
reserve p, q, r, s for Element of CQC-WFF(A);

theorem
  ( p '&' 'not' p ) => q in TAUT(A)
proof
  'not' q => 'not' ( p '&' 'not' p ) in TAUT(A) by Th1,LUKASI_1:13;
  hence thesis by LUKASI_1:35;
end;
