Lesson 236
Finite-State Machines
DFAs, NFAs & Regular Languages
1:00How finite-state machines work — the 5-tuple, DFA traces, NFAs, the subset construction, and the finite-memory limit that separates regular from non-regular languages.
By the end, you can
- Name and define all five components of the formal definition of a finite automaton.
- Trace a DFA on a given input string, state-by-state, and determine whether it accepts or rejects.
- Explain what the language of a machine is and why finite automata recognise exactly the regular languages.
- Distinguish a DFA from an NFA and describe how the subset construction converts one to the other.
- Calculate the worst-case number of DFA states produced by the subset construction from an NFA with n states.
- Explain why no DFA can recognise the language aⁿbⁿ, and connect this to the pumping lemma.
- Identify practical systems that use finite-state machines.
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