Designing compilers

Developing text editors

Simulating sequential circuits

All of these

regular

not regular

accepted by DFA

accepted by PDA

no edge should be labelled epsilon

from any given state, there can ′t be any token leading to two different states

both (a) and (b)

start state may not be there

one to one not onto

one to one and onto

not one to one and not onto

not one to one and onto

the symbols used have well-defined meaning

they are unnecessary, in reality

only form of the string of symbols is significant

Both (a) and (b)