Notes/UNB/Year 4/Semester 2/CS2333/2024-02-05.md

Lecture Topic: Non-determinism

So Far

All of the finite automata have been deterministic. This means that for any combination of state and input symbol there is exactly one transition defined

There are advantages to this

• Easier to trace a string through the finite automata Also some disadvantages
• Can make it harder to design

Example on whiteboard

In a non-deterministic finite automata (NFA), there are different paths, or choices you can make, so there can be more than one, or no transition defined for a given state.

To verify a string in a NFA, you need to follow each "choice" until a string completes, (ie, for two transitions defined, fork and check both paths)