For a small finite state mahcine we can use a simple model checker for a state safety property:

Algorithm: **`Find reachable state space'** (add successors of current set until closure):

S can be held explicitly in bit map form or symbolically as a BDD.

Variation 1: ignore safety property while finding reachable state space then finally check for all found states.

Variation 2: property to check might be a path property, so either

- Compile it to a checking automaton (becomes a state property of expanded NSF), or
- Expand it as we go (using modal mu calculus).

19: (C) 2008-11, DJ Greaves, University of Cambridge, Computer Laboratory.