"and B then> > there must exist an element of F> > such that the x in A is paired with> > some element of B, like .>> If x in A/\\B, then x in B, so>> F(x) in B and in F.>> > Similarly, the x in B must be paired> > with some element of A, like .>> If x in B, then there is an m in A such that x=F(m) (i.e., in> F).>> > If x is paired with itself in F,>> Then x=w.>> > then" . . . .