Second Lecture -- Deterministic Finite Automata
Wednesday, September 27.
Motivation
Natural model: states change at discrete time points, under external stimuli.
Example of revolver.
Definitions
5-tuple. Transition function 'delta'.
Represeting automata as directed graphs with labels on edges.
Definitions for languages:
- concatenation of strings, empty string
- concatenation of languages AB
- Powers (exponents) A^i
- star operation ('asterate' to Kozen)
Definitions for automata: extending 'delta' to 'delta hat', language accepted
by an automaton.
Examples of automata.