Automata theory is mainly concerned with Turing machines and all its relatives-in-spirit. $\lambda$-calculus is rather rarely mentioned in textbooks on automata theory. What's the common name of the ...
Epstein's (et al.) "Word Processing in Groups" is a quite comprehensive monograph on automatic groups, finite automata in geometric group theory, specific examples like braid groups, fundamental ...
In certain dark corners of computer science and group theory, one often wants to prove that a language is not a regular language (ie a language accepted by a finite state automaton). The only ...