theorem
  QuantNbr(p) = n & q is_subformula_of p implies QuantNbr(q) <= n
proof
  set L =the  PATH of q,p;
  set m = len L;
  assume that
A1: QuantNbr(p) = n and
A2: q is_subformula_of p;
  1 <= m by A2,Def5;
  then ex r st r = L.1 & QuantNbr(r) <= n by A1,A2,Th29;
  hence thesis by A2,Def5;
end;
