Here's what the problem says:
"Let F,G: B<->C be two relations. Prove: If F is total, G is determinate, and F G, then G F.
Hint: If you use quantifiers, you can, for any b:B, use instantiation for ∀ (9.13) on the predicate-logic definition of totality of F."
Seeing as how I have not a single clue on this green earth what as to what this question is asking, any help is greatly appreciated.