Tell me the concept of Nondeterministic Finite Automata

Question

Accepted Answer

⚹ Nondeterministic Finite Automata (NFA) is a theoretical model of computation used in computer science to represent and manipulate a set of strings. ⚹ ⚹ An NFA is defined by a 5-tuple $(Q, \Sigma, \delta, q_0, F)$ where: ⚹ ‖ ▪ ⋮ $Q$ ⋮ A finite set of states ‖ ‖ ▪ ⋮ $\Sigma$ ⋮ A finite set of input symbols (alphabet) ‖ ‖ ▪ ⋮ $\delta$ ⋮ A transition function $\delta: Q imes (\Sigma \cup \{\epsilon\}) ightarrow 2^Q$ ‖ ‖ ▪ ⋮ $q_0$ ⋮ The start state, where $q_0 \in Q$ ‖ ‖ ▪ ⋮ $F$ ⋮ A set of accept states, where $F \subseteq Q$ ‖ ⚹ The key difference between DFA and NFA is that in an NFA, for a given state and input symbol, the machine can transition to any number of possible next states, including zero. Additionally, NFAs can have $\epsilon$-transitions, which allow the machine to change states without consuming any input symbols. ⚹ ⚹ Here is an example of an NFA with states $Q = \{q_0, q_1, q_2\}$, alphabet $\Sigma = \{a, b\}$, start state $q_0$, and accept state $F = \{q_2\}$: ⚹ ```latex \documentclass{article} \usepackage{tikz} \usetikzlibrary{automata, positioning} \begin{document} \begin{tikzpicture}[shorten >=1pt, node distance=2cm, on grid, auto] ode[state, initial] (q_0) {$q_0$}; ode[state] (q_1) [right=of q_0] {$q_1$}; ode[state, accepting] (q_2) [right=of q_1] {$q_2$}; \path[->] (q_0) edge [loop above] node {a} () edge [bend left] node {b} (q_1) (q_1) edge [bend left] node {a} (q_0) edge [bend left] node {b} (q_2) (q_2) edge [loop above] node {a,b} (); \end{tikzpicture} \end{document} ``` ⚹ This LaTeX code will generate a graph representing the NFA. ⚹

Sia