(STRATEGY
    INNERMOST)

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