2022 October 12,
Carleton College, Joshua R. Davis
There are three problems to be submitted on paper.
A. Problem 3.14 (about PDAs with queues instead of stacks).
B. Problem 3.15bcde (about closure properties of the class of decidable languages).
C. Problem 3.16bcd (about closure properties of the class of recognizable languages).
And here's an optional study problem to ponder: Why can your argument for 3.15d not be adapted easily to show that the recognizable languages are also closed under complementation?