(STRATEGY
    INNERMOST)

(VAR
    L N X X1 X2)
(DATATYPES
    A = µX.< cons(X, X), 0, zeros, tt, s(X), nil, U11(X, X), U12(X, X), length(X) >)
(SIGNATURES
    a__zeros :: [] -> A
    a__U11 :: [A x A] -> A
    a__U12 :: [A x A] -> A
    a__length :: [A] -> A
    mark :: [A] -> A)
(RULES
    a__zeros() -> cons(0(),zeros())
    a__U11(tt(),L) -> a__U12(tt(),L)
    a__U12(tt(),L) ->
      s(a__length(mark(L)))
    a__length(nil()) -> 0()
    a__length(cons(N,L)) ->
      a__U11(tt(),L)
    mark(zeros()) -> a__zeros()
    mark(U11(X1,X2)) ->
      a__U11(mark(X1),X2)
    mark(U12(X1,X2)) ->
      a__U12(mark(X1),X2)
    mark(length(X)) ->
      a__length(mark(X))
    mark(cons(X1,X2)) ->
      cons(mark(X1),X2)
    mark(0()) -> 0()
    mark(tt()) -> tt()
    mark(s(X)) -> s(mark(X))
    mark(nil()) -> nil()
    a__zeros() -> zeros()
    a__U11(X1,X2) -> U11(X1,X2)
    a__U12(X1,X2) -> U12(X1,X2)
    a__length(X) -> length(X))