Formal Languages Questions
The main difference between an NFA (Non-deterministic Finite Automaton) and an epsilon-NFA (Epsilon Non-deterministic Finite Automaton) lies in the type of transitions they can have.
In an NFA, transitions are based on input symbols from the alphabet of the language being recognized. Each transition can only occur when a specific input symbol is read.
On the other hand, an epsilon-NFA can have epsilon transitions, also known as empty transitions or lambda transitions. These transitions can occur without consuming any input symbol. In other words, an epsilon-NFA can move from one state to another without reading any input.
The presence of epsilon transitions in an epsilon-NFA allows for more flexibility in the recognition process. It can potentially lead to a more concise representation of certain languages or regular expressions. However, it also increases the complexity of the automaton and the corresponding algorithms used for language recognition.