theorem
  All(All('not' a,A,G),B,G) '<' 'not' All(Ex(a,B,G),A,G)
proof
  'not' Ex(Ex(a,A,G),B,G) = All('not' Ex(a,A,G),B,G) & All('not' Ex(a,A,G)
  ,B,G ) = All(All('not' a,A,G),B,G) by BVFUNC_2:19;
  hence thesis by Th34;
end;
