Correctness of FLP

Lemma 2:

Let A be a 1-RCP with a bivalent initial execution.

There exists a decider for A.

-- FLP is correct if Lemmas 1 and 2 are correct:

Why?

Lemma 1: In any 1-RCP there is a bivalent initial

execution.

Together they mean that :

in any 1-RCP there exists a decider.