nphases — number of phases for this simulation. Invariant (posp nphases).
nst-extract-alists — what to extract at times 0...{N-1} from next-states. Invariant (true-listp nst-extract-alists).
out-extract-alists — what to extract at times 0...{N-1} from outputs. Invariant (true-listp out-extract-alists).
int-extract-alists — what to extract at times 0...{N-1} from internals. Invariant (true-listp int-extract-alists).
override-bits — flat list of state bits involved in overrides, i.e.,
just the override_value and override_decision vars. Invariant (symbol-listp override-bits).