PHD ENTRANCE EXAM: P, Q, R are three languages, if P and R are regular and if PQ = R, then

Thursday, 1 June 2017

P, Q, R are three languages, if P and R are regular and if PQ = R, then

1. Q has to be regular

2. Q cannot be regular

3. Q need not be regular (Right Answer)

4. Q cannot be a CFL

	1.	Q has to be regular
	2.	Q cannot be regular
	3.	Q need not be regular (Right Answer)
	4.	Q cannot be a CFL