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);

theorem
  FALSUM(A) is negative & the_argument_of FALSUM(A) = VERUM(A)
  by Th1;
