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);

theorem
  H is disjunctive implies H = (the_left_disjunct_of H) 'or' (
  the_right_disjunct_of H)
proof
  given F,G such that
A1: H = F 'or' G;
  the_left_disjunct_of H = F by A1,Th29;
  hence thesis by A1,Th29;
end;
