One week ago, I asked a question on math.stackexchange.com (http://math.stackexchange.com/questions/209120/a-question-on-intuitionistc-propositional-logic) . But nobody answered my question. So I presented it here:

In the Kripke's semantics of intuitionistic propositional logic, the frames are all partial ordered frames. Prove that:

Two finite rooted frames are isomorphic iff they validate the same formulas in the langusge of intuitionistic propositional logic.

Thanks very much.