(STRATEGY
    INNERMOST)

(VAR
    L N V V1 V2 X X1 X2)
(DATATYPES
    A = µX.< n__zeros, tt, n__0, n__length(X), n__s(X), n__cons(X, X), n__nil >)
(SIGNATURES
    zeros :: [] -> A
    U11 :: [A] -> A
    U21 :: [A] -> A
    U31 :: [A] -> A
    U41 :: [A x A] -> A
    U42 :: [A] -> A
    U51 :: [A x A] -> A
    U52 :: [A] -> A
    U61 :: [A x A x A] -> A
    U62 :: [A x A] -> A
    isNat :: [A] -> A
    isNatIList :: [A] -> A
    isNatList :: [A] -> A
    length :: [A] -> A
    0 :: [] -> A
    s :: [A] -> A
    cons :: [A x A] -> A
    nil :: [] -> A
    activate :: [A] -> A)
(RULES
    zeros() -> cons(0(),n__zeros())
    U11(tt()) -> tt()
    U21(tt()) -> tt()
    U31(tt()) -> tt()
    U41(tt(),V2) ->
      U42(isNatIList(activate(V2)))
    U42(tt()) -> tt()
    U51(tt(),V2) ->
      U52(isNatList(activate(V2)))
    U52(tt()) -> tt()
    U61(tt(),L,N) ->
      U62(isNat(activate(N))
         ,activate(L))
    U62(tt(),L) ->
      s(length(activate(L)))
    isNat(n__0()) -> tt()
    isNat(n__length(V1)) ->
      U11(isNatList(activate(V1)))
    isNat(n__s(V1)) ->
      U21(isNat(activate(V1)))
    isNatIList(V) ->
      U31(isNatList(activate(V)))
    isNatIList(n__zeros()) -> tt()
    isNatIList(n__cons(V1,V2)) ->
      U41(isNat(activate(V1))
         ,activate(V2))
    isNatList(n__nil()) -> tt()
    isNatList(n__cons(V1,V2)) ->
      U51(isNat(activate(V1))
         ,activate(V2))
    length(nil()) -> 0()
    length(cons(N,L)) ->
      U61(isNatList(activate(L))
         ,activate(L)
         ,N)
    zeros() -> n__zeros()
    0() -> n__0()
    length(X) -> n__length(X)
    s(X) -> n__s(X)
    cons(X1,X2) -> n__cons(X1,X2)
    nil() -> n__nil()
    activate(n__zeros()) -> zeros()
    activate(n__0()) -> 0()
    activate(n__length(X)) ->
      length(X)
    activate(n__s(X)) -> s(X)
    activate(n__cons(X1,X2)) ->
      cons(X1,X2)
    activate(n__nil()) -> nil()
    activate(X) -> X)