finite state automation
2-way linear bounded automata
push down automata
both 1) 2-way linear bounded automata and 2) push down automata
context free language
context-sensitive language
regular language
recursive enumerable language
union, intersection
union, kleene closure
intersection, complement
complement, kleene closure
L (G) = φ
L(G) = an
L (G) = a*
L (G) = anban
an^2
n2a
2an
none of these