R
Rishtaara
Discrete Mathematics
Lesson 9 of 11Article15 min

Automata & Formal Languages Preview

You do not need full theory here — learn the landscape so algorithms and compilers courses feel connected to discrete foundations.

Machines that recognise patterns

You do not need full theory here — learn the landscape so algorithms and compilers courses feel connected to discrete foundations.

  • DFA/NFA: finite memory recognisers for regular languages.
  • Regular expressions ↔ finite automata (Kleene).
  • Context-free grammars / pushdown automata for nested structure (e.g. balanced parentheses).
  • Turing machines: the standard model of computability.
Undecidability results (halting problem) show hard limits: some questions no algorithm can answer for all inputs.