Prerequisite – Finite Automata Introduction, Designing Finite Automata from Regular Expression (Set 1)

**∈-NFA** is similar to the NFA but have minor difference by epsilon move. This automaton replaces the transition function with the one that allows the empty string ∈ as a possible input. The transitions without consuming an input symbol are called ∈-transitions.

In the state diagrams, they are usually labeled with the Greek letter ∈. ∈-transitions provide a convenient way of modeling the systems whose current states are not precisely known: i.e., if we are modeling a system and it is not clear whether the current state (after processing some input string) should be q or q’, then we can add an ∈-transition between these two states, thus putting the automaton in both states simultaneously.

**Common regular expression used in make ∈-NFA:**

Example: Create a ∈-NFA for regular expression: (a/b)*a

Refer for – Conversion from NFA to DFA, Minimization of DFA

Attention reader! Don’t stop learning now. Get hold of all the important CS Theory concepts for SDE interviews with the CS Theory Course at a student-friendly price and become industry ready.

## Recommended Posts:

- Regular Expressions, Regular Grammar and Regular Languages
- Star Height of Regular Expression and Regular Language
- Designing Finite Automata from Regular Expression (Set 1)
- Generating regular expression from Finite Automata
- Designing Finite Automata from Regular Expression (Set 6)
- Designing Finite Automata from Regular Expression (Set 2)
- Designing Finite Automata from Regular Expression (Set 3)
- Designing Finite Automata from Regular Expression (Set 4)
- Designing Finite Automata from Regular Expression (Set 5)
- Designing Finite Automata from Regular Expression (Set 7)
- Designing Finite Automata from Regular Expression (Set 8)
- Regular Expression Vs Context Free Grammar
- Union and Intersection of Regular languages with CFL
- How to identify if a language is regular or not
- Regular Graph in Graph Theory
- Closure properties of Regular languages

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.