# Behavior of specific PDA for a certain input

Suppose we're given the non-deterministic PDA shown below which reads from the alphabet $$\sum = \lbrace a,b \rbrace$$. How will this PDA behave if we pass it the string $$ba$$? We read $$b$$ first and push $$b$$ to the stack, but when we read $$a$$ I get confused. My assumption is that we fork into two new branches - one in which $$b$$ was popped and one in which $$a$$ was pushed. Is this correct? If not, can you tell me where I go wrong?

Thank you very much!

• You're correct. – Rick Decker Feb 27 at 15:57