Examples of Finite State Automata

The first two examples of FSA's that we demonstrated on the previous two pages are exceedingly simple.  Still, you may already have a pretty good idea of how FSA's are constructed.  Rather than make you wade through a bunch of pages of more examples of FSA's, we provide here a list of examples that you can peruse at your leisure.  Have fun exploring them until you become comfortable with FSA's and the kinds of problems they can solve. 

Each example FSA recognizes a particular set of strings, as noted below:

• all binary strings that contain a substring 101.
• all binary strings that contain a substring of either 101 or 010.
• all binary numbers, N, such that N mod 3 is either 0 or 2.
• all binary numbers N such that N mod 5 is 4.
• all variable names for some programming language.
• all numbers that represent an integer, a fixed point, or a floating point for some programming language.