(STRATEGY
    INNERMOST)

(VAR
    X X1 X2 X3 Y)
(DATATYPES
    A = µX.< mark(X), b, c, ok(X) >)
(SIGNATURES
    active :: [A] -> A
    g :: [A] -> A
    proper :: [A] -> A
    f :: [A x A x A] -> A
    top :: [A] -> A)
(RULES
    active(f(X,g(X),Y)) -> mark(f(Y
                                 ,Y
                                 ,Y))
    active(g(b())) -> mark(c())
    active(b()) -> mark(c())
    active(g(X)) -> g(active(X))
    g(mark(X)) -> mark(g(X))
    proper(f(X1,X2,X3)) ->
      f(proper(X1)
       ,proper(X2)
       ,proper(X3))
    proper(g(X)) -> g(proper(X))
    proper(b()) -> ok(b())
    proper(c()) -> ok(c())
    f(ok(X1),ok(X2),ok(X3)) ->
      ok(f(X1,X2,X3))
    g(ok(X)) -> ok(g(X))
    top(mark(X)) -> top(proper(X))
    top(ok(X)) -> top(active(X)))