1. Boolean circuits and P /poly 2. Uniformly generated circuits 3. Turing machines that take advice See

In order to give a push-down automaton which realizes the above mentioned idea, we need a context-free grammar which generates L. In the former case we compare a with the scanned

A Turing machine either fails to accept an input because it rejects it (entering q reject ) or. because it loops (= does

I A Turing machine either fails to accept an input I because it rejects it (entering q reject ) or. I because it loops (= does

I A Turing machine either fails to accept an input I because it rejects it (entering q reject ) or. I because it loops (= does

Whenever M 0 is in one of the primed states, it does not change the tape, switches to the unprimed state q and moves left.. For every transition of M with neutral move, M 0 takes

Gabriele R¨ oger (University of Basel) Theory of Computer Science April 12, 2021 2 /

The first tape always contains w , the second tape corresponds to the content of N’s tape on some branch of the computation tree and the third tape tracks the position in

accept exactly the regular languages, push-down automata exactly the context-free languages. Are there automata models