reserve A for QC-alphabet;
reserve sq for FinSequence,
  x,y,z for bound_QC-variable of A,
  p,q,p1,p2,q1 for Element of QC-WFF(A);
reserve s,t for bound_QC-variable of A;
reserve F,G,H,H1 for Element of QC-WFF(A);
reserve x,y,z for bound_QC-variable of A,
  k,n,m for Nat,
  P for ( QC-pred_symbol of k, A),
  V for QC-variable_list of k, A;
reserve L,L9 for FinSequence;

theorem Th64:
  not F is_proper_subformula_of VERUM(A)
proof
  assume not thesis;
  then consider G such that
A1: G is_immediate_constituent_of VERUM(A) by Th55;
  thus thesis by A1,Th41;
end;
