Give a decision procedure to answer each of the following questions:

Given a regular expression a and a PDA M, is the language accepted by M a subset of the language generated by ?

Given a context-free grammar G and two strings S1 and S2 , does G generate S1S2?

Given a context-free grammar G, does G generate at least three strings?

Given a context-free grammar G. docs G generate any even length strings?

Given a regular grammar G. is L(G) context-free

G is not mentioned. it is any string in the grammar