Mental note: If for some really bizzare reason I might need to draw lines pointing at circles, or try to figure out if
S -> aSb|aS|ε actually matches L={a^ib^j| i>=j}, I will try to solve the problem by hand first. However, in event I am really lazy, and forgot how to convert an NFA to DFA or actually want to trace the stack of a PDA matching a CFG, I will download JFLAP and use it.
Now, why did I discover this thing after I wrote my final exam? So that I could learn how to do it by hand, that’s why. It would have rocked my world about 3 months ago, but I probably would have failed the exams, relaying on it to do everything for me.
Oh, and notation it uses for CFG/PDA is somewhat different from one used in Sipser (Which is a damn fine book, BTW. Unlike Lawson it actually covers CFLs.).
P.S Mark Lawson actually makes reasonably good notes available on his page about basic automata. It still doesn’t go into CFLs/PDAs.