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

theorem
  ( p => q ) => ( 'not' p 'or' q ) in TAUT(A)
proof
A1: ( 'not' 'not' p => p ) => (( p => q ) => ( 'not' 'not' p => q )) in TAUT(A)
  by LUKASI_1:1;
  ( 'not' 'not' p => q ) = ( 'not' p 'or' q ) & 'not' 'not' p => p in TAUT(A)
  by Lm1,LUKASI_1:25;
  hence thesis by A1,CQC_THE1:46;
end;
