reserve Al for QC-alphabet;
reserve p,q,p1,p2,q1 for Element of CQC-WFF(Al),
  k for Element of NAT,
  f,f1,f2,g for FinSequence of CQC-WFF(Al),
  a,b,b1,b2,c,i,n for Nat;
reserve P for Permutation of dom f;

theorem Th25:
  |- f^<*p*> & |- f^<*'not' p*> implies |- f^<*q*>
proof
A1: Ant(f^<*p*>) = f & Suc(f^<*p*>) = p by CALCUL_1:5;
  assume |- f^<*p*> & |- f^<*'not' p*>;
  hence thesis by A1,CALCUL_1:44;
end;
