(STRATEGY
    INNERMOST)

(VAR
    X)
(DATATYPES
    A = µX.< a, mark(X), ok(X) >)
(SIGNATURES
    active :: [A] -> A
    g :: [A] -> A
    proper :: [A] -> A
    f :: [A] -> A
    top :: [A] -> A)
(RULES
    active(f(f(a()))) ->
      mark(f(g(f(a()))))
    active(g(X)) -> g(active(X))
    g(mark(X)) -> mark(g(X))
    proper(f(X)) -> f(proper(X))
    proper(a()) -> ok(a())
    proper(g(X)) -> g(proper(X))
    f(ok(X)) -> ok(f(X))
    g(ok(X)) -> ok(g(X))
    top(mark(X)) -> top(proper(X))
    top(ok(X)) -> top(active(X)))