MODULE        Vanilla.

IMPORT        OM2.

PREDICATE     Solve : OFormula.
DELAY         Solve(x) UNTIL NONVAR(x).

Solve(Empty).

Solve(x And y) <-
              Solve(x) &
              Solve(y).

Solve(Not x) <-
              ~ Solve(x).

Solve(x) <-
              Statement(x If y) &
              Solve(y).
