app2(f, 0) -> true
app2(f, 1) -> false
app2(f, app2(s, x)) -> app2(f, x)
app2(app2(app2(if, true), app2(s, x)), app2(s, y)) -> app2(s, x)
app2(app2(app2(if, false), app2(s, x)), app2(s, y)) -> app2(s, y)
app2(app2(g, x), app2(c, y)) -> app2(c, app2(app2(g, x), y))
app2(app2(g, x), app2(c, y)) -> app2(app2(g, x), app2(app2(app2(if, app2(f, x)), app2(c, app2(app2(g, app2(s, x)), y))), app2(c, y)))
app2(app2(map, fun), nil) -> nil
app2(app2(map, fun), app2(app2(cons, x), xs)) -> app2(app2(cons, app2(fun, x)), app2(app2(map, fun), xs))
app2(app2(filter, fun), nil) -> nil
app2(app2(filter, fun), app2(app2(cons, x), xs)) -> app2(app2(app2(app2(filter2, app2(fun, x)), fun), x), xs)
app2(app2(app2(app2(filter2, true), fun), x), xs) -> app2(app2(cons, x), app2(app2(filter, fun), xs))
app2(app2(app2(app2(filter2, false), fun), x), xs) -> app2(app2(filter, fun), xs)
↳ QTRS
↳ DependencyPairsProof
app2(f, 0) -> true
app2(f, 1) -> false
app2(f, app2(s, x)) -> app2(f, x)
app2(app2(app2(if, true), app2(s, x)), app2(s, y)) -> app2(s, x)
app2(app2(app2(if, false), app2(s, x)), app2(s, y)) -> app2(s, y)
app2(app2(g, x), app2(c, y)) -> app2(c, app2(app2(g, x), y))
app2(app2(g, x), app2(c, y)) -> app2(app2(g, x), app2(app2(app2(if, app2(f, x)), app2(c, app2(app2(g, app2(s, x)), y))), app2(c, y)))
app2(app2(map, fun), nil) -> nil
app2(app2(map, fun), app2(app2(cons, x), xs)) -> app2(app2(cons, app2(fun, x)), app2(app2(map, fun), xs))
app2(app2(filter, fun), nil) -> nil
app2(app2(filter, fun), app2(app2(cons, x), xs)) -> app2(app2(app2(app2(filter2, app2(fun, x)), fun), x), xs)
app2(app2(app2(app2(filter2, true), fun), x), xs) -> app2(app2(cons, x), app2(app2(filter, fun), xs))
app2(app2(app2(app2(filter2, false), fun), x), xs) -> app2(app2(filter, fun), xs)
APP2(f, app2(s, x)) -> APP2(f, x)
APP2(app2(map, fun), app2(app2(cons, x), xs)) -> APP2(app2(cons, app2(fun, x)), app2(app2(map, fun), xs))
APP2(app2(g, x), app2(c, y)) -> APP2(app2(g, app2(s, x)), y)
APP2(app2(filter, fun), app2(app2(cons, x), xs)) -> APP2(app2(app2(filter2, app2(fun, x)), fun), x)
APP2(app2(filter, fun), app2(app2(cons, x), xs)) -> APP2(app2(app2(app2(filter2, app2(fun, x)), fun), x), xs)
APP2(app2(app2(app2(filter2, true), fun), x), xs) -> APP2(app2(cons, x), app2(app2(filter, fun), xs))
APP2(app2(g, x), app2(c, y)) -> APP2(f, x)
APP2(app2(g, x), app2(c, y)) -> APP2(s, x)
APP2(app2(map, fun), app2(app2(cons, x), xs)) -> APP2(fun, x)
APP2(app2(filter, fun), app2(app2(cons, x), xs)) -> APP2(filter2, app2(fun, x))
APP2(app2(g, x), app2(c, y)) -> APP2(app2(app2(if, app2(f, x)), app2(c, app2(app2(g, app2(s, x)), y))), app2(c, y))
APP2(app2(g, x), app2(c, y)) -> APP2(app2(g, x), app2(app2(app2(if, app2(f, x)), app2(c, app2(app2(g, app2(s, x)), y))), app2(c, y)))
APP2(app2(g, x), app2(c, y)) -> APP2(if, app2(f, x))
APP2(app2(app2(app2(filter2, true), fun), x), xs) -> APP2(app2(filter, fun), xs)
APP2(app2(g, x), app2(c, y)) -> APP2(c, app2(app2(g, x), y))
APP2(app2(filter, fun), app2(app2(cons, x), xs)) -> APP2(app2(filter2, app2(fun, x)), fun)
APP2(app2(app2(app2(filter2, false), fun), x), xs) -> APP2(filter, fun)
APP2(app2(g, x), app2(c, y)) -> APP2(c, app2(app2(g, app2(s, x)), y))
APP2(app2(map, fun), app2(app2(cons, x), xs)) -> APP2(app2(map, fun), xs)
APP2(app2(filter, fun), app2(app2(cons, x), xs)) -> APP2(fun, x)
APP2(app2(app2(app2(filter2, true), fun), x), xs) -> APP2(filter, fun)
APP2(app2(g, x), app2(c, y)) -> APP2(g, app2(s, x))
APP2(app2(g, x), app2(c, y)) -> APP2(app2(g, x), y)
APP2(app2(g, x), app2(c, y)) -> APP2(app2(if, app2(f, x)), app2(c, app2(app2(g, app2(s, x)), y)))
APP2(app2(app2(app2(filter2, true), fun), x), xs) -> APP2(cons, x)
APP2(app2(app2(app2(filter2, false), fun), x), xs) -> APP2(app2(filter, fun), xs)
APP2(app2(map, fun), app2(app2(cons, x), xs)) -> APP2(cons, app2(fun, x))
app2(f, 0) -> true
app2(f, 1) -> false
app2(f, app2(s, x)) -> app2(f, x)
app2(app2(app2(if, true), app2(s, x)), app2(s, y)) -> app2(s, x)
app2(app2(app2(if, false), app2(s, x)), app2(s, y)) -> app2(s, y)
app2(app2(g, x), app2(c, y)) -> app2(c, app2(app2(g, x), y))
app2(app2(g, x), app2(c, y)) -> app2(app2(g, x), app2(app2(app2(if, app2(f, x)), app2(c, app2(app2(g, app2(s, x)), y))), app2(c, y)))
app2(app2(map, fun), nil) -> nil
app2(app2(map, fun), app2(app2(cons, x), xs)) -> app2(app2(cons, app2(fun, x)), app2(app2(map, fun), xs))
app2(app2(filter, fun), nil) -> nil
app2(app2(filter, fun), app2(app2(cons, x), xs)) -> app2(app2(app2(app2(filter2, app2(fun, x)), fun), x), xs)
app2(app2(app2(app2(filter2, true), fun), x), xs) -> app2(app2(cons, x), app2(app2(filter, fun), xs))
app2(app2(app2(app2(filter2, false), fun), x), xs) -> app2(app2(filter, fun), xs)
↳ QTRS
↳ DependencyPairsProof
↳ QDP
↳ DependencyGraphProof
APP2(f, app2(s, x)) -> APP2(f, x)
APP2(app2(map, fun), app2(app2(cons, x), xs)) -> APP2(app2(cons, app2(fun, x)), app2(app2(map, fun), xs))
APP2(app2(g, x), app2(c, y)) -> APP2(app2(g, app2(s, x)), y)
APP2(app2(filter, fun), app2(app2(cons, x), xs)) -> APP2(app2(app2(filter2, app2(fun, x)), fun), x)
APP2(app2(filter, fun), app2(app2(cons, x), xs)) -> APP2(app2(app2(app2(filter2, app2(fun, x)), fun), x), xs)
APP2(app2(app2(app2(filter2, true), fun), x), xs) -> APP2(app2(cons, x), app2(app2(filter, fun), xs))
APP2(app2(g, x), app2(c, y)) -> APP2(f, x)
APP2(app2(g, x), app2(c, y)) -> APP2(s, x)
APP2(app2(map, fun), app2(app2(cons, x), xs)) -> APP2(fun, x)
APP2(app2(filter, fun), app2(app2(cons, x), xs)) -> APP2(filter2, app2(fun, x))
APP2(app2(g, x), app2(c, y)) -> APP2(app2(app2(if, app2(f, x)), app2(c, app2(app2(g, app2(s, x)), y))), app2(c, y))
APP2(app2(g, x), app2(c, y)) -> APP2(app2(g, x), app2(app2(app2(if, app2(f, x)), app2(c, app2(app2(g, app2(s, x)), y))), app2(c, y)))
APP2(app2(g, x), app2(c, y)) -> APP2(if, app2(f, x))
APP2(app2(app2(app2(filter2, true), fun), x), xs) -> APP2(app2(filter, fun), xs)
APP2(app2(g, x), app2(c, y)) -> APP2(c, app2(app2(g, x), y))
APP2(app2(filter, fun), app2(app2(cons, x), xs)) -> APP2(app2(filter2, app2(fun, x)), fun)
APP2(app2(app2(app2(filter2, false), fun), x), xs) -> APP2(filter, fun)
APP2(app2(g, x), app2(c, y)) -> APP2(c, app2(app2(g, app2(s, x)), y))
APP2(app2(map, fun), app2(app2(cons, x), xs)) -> APP2(app2(map, fun), xs)
APP2(app2(filter, fun), app2(app2(cons, x), xs)) -> APP2(fun, x)
APP2(app2(app2(app2(filter2, true), fun), x), xs) -> APP2(filter, fun)
APP2(app2(g, x), app2(c, y)) -> APP2(g, app2(s, x))
APP2(app2(g, x), app2(c, y)) -> APP2(app2(g, x), y)
APP2(app2(g, x), app2(c, y)) -> APP2(app2(if, app2(f, x)), app2(c, app2(app2(g, app2(s, x)), y)))
APP2(app2(app2(app2(filter2, true), fun), x), xs) -> APP2(cons, x)
APP2(app2(app2(app2(filter2, false), fun), x), xs) -> APP2(app2(filter, fun), xs)
APP2(app2(map, fun), app2(app2(cons, x), xs)) -> APP2(cons, app2(fun, x))
app2(f, 0) -> true
app2(f, 1) -> false
app2(f, app2(s, x)) -> app2(f, x)
app2(app2(app2(if, true), app2(s, x)), app2(s, y)) -> app2(s, x)
app2(app2(app2(if, false), app2(s, x)), app2(s, y)) -> app2(s, y)
app2(app2(g, x), app2(c, y)) -> app2(c, app2(app2(g, x), y))
app2(app2(g, x), app2(c, y)) -> app2(app2(g, x), app2(app2(app2(if, app2(f, x)), app2(c, app2(app2(g, app2(s, x)), y))), app2(c, y)))
app2(app2(map, fun), nil) -> nil
app2(app2(map, fun), app2(app2(cons, x), xs)) -> app2(app2(cons, app2(fun, x)), app2(app2(map, fun), xs))
app2(app2(filter, fun), nil) -> nil
app2(app2(filter, fun), app2(app2(cons, x), xs)) -> app2(app2(app2(app2(filter2, app2(fun, x)), fun), x), xs)
app2(app2(app2(app2(filter2, true), fun), x), xs) -> app2(app2(cons, x), app2(app2(filter, fun), xs))
app2(app2(app2(app2(filter2, false), fun), x), xs) -> app2(app2(filter, fun), xs)
↳ QTRS
↳ DependencyPairsProof
↳ QDP
↳ DependencyGraphProof
↳ AND
↳ QDP
↳ QDPOrderProof
↳ QDP
↳ QDP
APP2(f, app2(s, x)) -> APP2(f, x)
app2(f, 0) -> true
app2(f, 1) -> false
app2(f, app2(s, x)) -> app2(f, x)
app2(app2(app2(if, true), app2(s, x)), app2(s, y)) -> app2(s, x)
app2(app2(app2(if, false), app2(s, x)), app2(s, y)) -> app2(s, y)
app2(app2(g, x), app2(c, y)) -> app2(c, app2(app2(g, x), y))
app2(app2(g, x), app2(c, y)) -> app2(app2(g, x), app2(app2(app2(if, app2(f, x)), app2(c, app2(app2(g, app2(s, x)), y))), app2(c, y)))
app2(app2(map, fun), nil) -> nil
app2(app2(map, fun), app2(app2(cons, x), xs)) -> app2(app2(cons, app2(fun, x)), app2(app2(map, fun), xs))
app2(app2(filter, fun), nil) -> nil
app2(app2(filter, fun), app2(app2(cons, x), xs)) -> app2(app2(app2(app2(filter2, app2(fun, x)), fun), x), xs)
app2(app2(app2(app2(filter2, true), fun), x), xs) -> app2(app2(cons, x), app2(app2(filter, fun), xs))
app2(app2(app2(app2(filter2, false), fun), x), xs) -> app2(app2(filter, fun), xs)
The following pairs can be oriented strictly and are deleted.
The remaining pairs can at least be oriented weakly.
APP2(f, app2(s, x)) -> APP2(f, x)
POL(APP2(x1, x2)) = 2·x2
POL(app2(x1, x2)) = 1 + 2·x2
POL(f) = 0
POL(s) = 2
↳ QTRS
↳ DependencyPairsProof
↳ QDP
↳ DependencyGraphProof
↳ AND
↳ QDP
↳ QDPOrderProof
↳ QDP
↳ PisEmptyProof
↳ QDP
↳ QDP
app2(f, 0) -> true
app2(f, 1) -> false
app2(f, app2(s, x)) -> app2(f, x)
app2(app2(app2(if, true), app2(s, x)), app2(s, y)) -> app2(s, x)
app2(app2(app2(if, false), app2(s, x)), app2(s, y)) -> app2(s, y)
app2(app2(g, x), app2(c, y)) -> app2(c, app2(app2(g, x), y))
app2(app2(g, x), app2(c, y)) -> app2(app2(g, x), app2(app2(app2(if, app2(f, x)), app2(c, app2(app2(g, app2(s, x)), y))), app2(c, y)))
app2(app2(map, fun), nil) -> nil
app2(app2(map, fun), app2(app2(cons, x), xs)) -> app2(app2(cons, app2(fun, x)), app2(app2(map, fun), xs))
app2(app2(filter, fun), nil) -> nil
app2(app2(filter, fun), app2(app2(cons, x), xs)) -> app2(app2(app2(app2(filter2, app2(fun, x)), fun), x), xs)
app2(app2(app2(app2(filter2, true), fun), x), xs) -> app2(app2(cons, x), app2(app2(filter, fun), xs))
app2(app2(app2(app2(filter2, false), fun), x), xs) -> app2(app2(filter, fun), xs)
↳ QTRS
↳ DependencyPairsProof
↳ QDP
↳ DependencyGraphProof
↳ AND
↳ QDP
↳ QDP
↳ QDPOrderProof
↳ QDP
APP2(app2(g, x), app2(c, y)) -> APP2(app2(g, x), y)
APP2(app2(g, x), app2(c, y)) -> APP2(app2(g, app2(s, x)), y)
app2(f, 0) -> true
app2(f, 1) -> false
app2(f, app2(s, x)) -> app2(f, x)
app2(app2(app2(if, true), app2(s, x)), app2(s, y)) -> app2(s, x)
app2(app2(app2(if, false), app2(s, x)), app2(s, y)) -> app2(s, y)
app2(app2(g, x), app2(c, y)) -> app2(c, app2(app2(g, x), y))
app2(app2(g, x), app2(c, y)) -> app2(app2(g, x), app2(app2(app2(if, app2(f, x)), app2(c, app2(app2(g, app2(s, x)), y))), app2(c, y)))
app2(app2(map, fun), nil) -> nil
app2(app2(map, fun), app2(app2(cons, x), xs)) -> app2(app2(cons, app2(fun, x)), app2(app2(map, fun), xs))
app2(app2(filter, fun), nil) -> nil
app2(app2(filter, fun), app2(app2(cons, x), xs)) -> app2(app2(app2(app2(filter2, app2(fun, x)), fun), x), xs)
app2(app2(app2(app2(filter2, true), fun), x), xs) -> app2(app2(cons, x), app2(app2(filter, fun), xs))
app2(app2(app2(app2(filter2, false), fun), x), xs) -> app2(app2(filter, fun), xs)
The following pairs can be oriented strictly and are deleted.
The remaining pairs can at least be oriented weakly.
APP2(app2(g, x), app2(c, y)) -> APP2(app2(g, x), y)
Used ordering: Polynomial interpretation [21]:
APP2(app2(g, x), app2(c, y)) -> APP2(app2(g, app2(s, x)), y)
POL(APP2(x1, x2)) = x1 + x2
POL(app2(x1, x2)) = x1 + x2
POL(c) = 1
POL(g) = 0
POL(s) = 1
↳ QTRS
↳ DependencyPairsProof
↳ QDP
↳ DependencyGraphProof
↳ AND
↳ QDP
↳ QDP
↳ QDPOrderProof
↳ QDP
↳ QDPOrderProof
↳ QDP
APP2(app2(g, x), app2(c, y)) -> APP2(app2(g, app2(s, x)), y)
app2(f, 0) -> true
app2(f, 1) -> false
app2(f, app2(s, x)) -> app2(f, x)
app2(app2(app2(if, true), app2(s, x)), app2(s, y)) -> app2(s, x)
app2(app2(app2(if, false), app2(s, x)), app2(s, y)) -> app2(s, y)
app2(app2(g, x), app2(c, y)) -> app2(c, app2(app2(g, x), y))
app2(app2(g, x), app2(c, y)) -> app2(app2(g, x), app2(app2(app2(if, app2(f, x)), app2(c, app2(app2(g, app2(s, x)), y))), app2(c, y)))
app2(app2(map, fun), nil) -> nil
app2(app2(map, fun), app2(app2(cons, x), xs)) -> app2(app2(cons, app2(fun, x)), app2(app2(map, fun), xs))
app2(app2(filter, fun), nil) -> nil
app2(app2(filter, fun), app2(app2(cons, x), xs)) -> app2(app2(app2(app2(filter2, app2(fun, x)), fun), x), xs)
app2(app2(app2(app2(filter2, true), fun), x), xs) -> app2(app2(cons, x), app2(app2(filter, fun), xs))
app2(app2(app2(app2(filter2, false), fun), x), xs) -> app2(app2(filter, fun), xs)
The following pairs can be oriented strictly and are deleted.
The remaining pairs can at least be oriented weakly.
APP2(app2(g, x), app2(c, y)) -> APP2(app2(g, app2(s, x)), y)
POL(APP2(x1, x2)) = x2
POL(app2(x1, x2)) = 1 + 2·x2
POL(c) = 2
POL(g) = 0
POL(s) = 2
↳ QTRS
↳ DependencyPairsProof
↳ QDP
↳ DependencyGraphProof
↳ AND
↳ QDP
↳ QDP
↳ QDPOrderProof
↳ QDP
↳ QDPOrderProof
↳ QDP
↳ PisEmptyProof
↳ QDP
app2(f, 0) -> true
app2(f, 1) -> false
app2(f, app2(s, x)) -> app2(f, x)
app2(app2(app2(if, true), app2(s, x)), app2(s, y)) -> app2(s, x)
app2(app2(app2(if, false), app2(s, x)), app2(s, y)) -> app2(s, y)
app2(app2(g, x), app2(c, y)) -> app2(c, app2(app2(g, x), y))
app2(app2(g, x), app2(c, y)) -> app2(app2(g, x), app2(app2(app2(if, app2(f, x)), app2(c, app2(app2(g, app2(s, x)), y))), app2(c, y)))
app2(app2(map, fun), nil) -> nil
app2(app2(map, fun), app2(app2(cons, x), xs)) -> app2(app2(cons, app2(fun, x)), app2(app2(map, fun), xs))
app2(app2(filter, fun), nil) -> nil
app2(app2(filter, fun), app2(app2(cons, x), xs)) -> app2(app2(app2(app2(filter2, app2(fun, x)), fun), x), xs)
app2(app2(app2(app2(filter2, true), fun), x), xs) -> app2(app2(cons, x), app2(app2(filter, fun), xs))
app2(app2(app2(app2(filter2, false), fun), x), xs) -> app2(app2(filter, fun), xs)
↳ QTRS
↳ DependencyPairsProof
↳ QDP
↳ DependencyGraphProof
↳ AND
↳ QDP
↳ QDP
↳ QDP
↳ QDPOrderProof
APP2(app2(app2(app2(filter2, true), fun), x), xs) -> APP2(app2(filter, fun), xs)
APP2(app2(map, fun), app2(app2(cons, x), xs)) -> APP2(fun, x)
APP2(app2(filter, fun), app2(app2(cons, x), xs)) -> APP2(app2(app2(app2(filter2, app2(fun, x)), fun), x), xs)
APP2(app2(app2(app2(filter2, false), fun), x), xs) -> APP2(app2(filter, fun), xs)
APP2(app2(filter, fun), app2(app2(cons, x), xs)) -> APP2(fun, x)
APP2(app2(map, fun), app2(app2(cons, x), xs)) -> APP2(app2(map, fun), xs)
app2(f, 0) -> true
app2(f, 1) -> false
app2(f, app2(s, x)) -> app2(f, x)
app2(app2(app2(if, true), app2(s, x)), app2(s, y)) -> app2(s, x)
app2(app2(app2(if, false), app2(s, x)), app2(s, y)) -> app2(s, y)
app2(app2(g, x), app2(c, y)) -> app2(c, app2(app2(g, x), y))
app2(app2(g, x), app2(c, y)) -> app2(app2(g, x), app2(app2(app2(if, app2(f, x)), app2(c, app2(app2(g, app2(s, x)), y))), app2(c, y)))
app2(app2(map, fun), nil) -> nil
app2(app2(map, fun), app2(app2(cons, x), xs)) -> app2(app2(cons, app2(fun, x)), app2(app2(map, fun), xs))
app2(app2(filter, fun), nil) -> nil
app2(app2(filter, fun), app2(app2(cons, x), xs)) -> app2(app2(app2(app2(filter2, app2(fun, x)), fun), x), xs)
app2(app2(app2(app2(filter2, true), fun), x), xs) -> app2(app2(cons, x), app2(app2(filter, fun), xs))
app2(app2(app2(app2(filter2, false), fun), x), xs) -> app2(app2(filter, fun), xs)
The following pairs can be oriented strictly and are deleted.
The remaining pairs can at least be oriented weakly.
APP2(app2(map, fun), app2(app2(cons, x), xs)) -> APP2(fun, x)
APP2(app2(filter, fun), app2(app2(cons, x), xs)) -> APP2(app2(app2(app2(filter2, app2(fun, x)), fun), x), xs)
APP2(app2(filter, fun), app2(app2(cons, x), xs)) -> APP2(fun, x)
APP2(app2(map, fun), app2(app2(cons, x), xs)) -> APP2(app2(map, fun), xs)
Used ordering: Polynomial interpretation [21]:
APP2(app2(app2(app2(filter2, true), fun), x), xs) -> APP2(app2(filter, fun), xs)
APP2(app2(app2(app2(filter2, false), fun), x), xs) -> APP2(app2(filter, fun), xs)
POL(0) = 0
POL(1) = 0
POL(APP2(x1, x2)) = x2
POL(app2(x1, x2)) = 2·x1 + 2·x2
POL(c) = 1
POL(cons) = 2
POL(f) = 2
POL(false) = 2
POL(filter) = 2
POL(filter2) = 1
POL(g) = 2
POL(if) = 2
POL(map) = 1
POL(nil) = 2
POL(s) = 1
POL(true) = 2
↳ QTRS
↳ DependencyPairsProof
↳ QDP
↳ DependencyGraphProof
↳ AND
↳ QDP
↳ QDP
↳ QDP
↳ QDPOrderProof
↳ QDP
↳ DependencyGraphProof
APP2(app2(app2(app2(filter2, true), fun), x), xs) -> APP2(app2(filter, fun), xs)
APP2(app2(app2(app2(filter2, false), fun), x), xs) -> APP2(app2(filter, fun), xs)
app2(f, 0) -> true
app2(f, 1) -> false
app2(f, app2(s, x)) -> app2(f, x)
app2(app2(app2(if, true), app2(s, x)), app2(s, y)) -> app2(s, x)
app2(app2(app2(if, false), app2(s, x)), app2(s, y)) -> app2(s, y)
app2(app2(g, x), app2(c, y)) -> app2(c, app2(app2(g, x), y))
app2(app2(g, x), app2(c, y)) -> app2(app2(g, x), app2(app2(app2(if, app2(f, x)), app2(c, app2(app2(g, app2(s, x)), y))), app2(c, y)))
app2(app2(map, fun), nil) -> nil
app2(app2(map, fun), app2(app2(cons, x), xs)) -> app2(app2(cons, app2(fun, x)), app2(app2(map, fun), xs))
app2(app2(filter, fun), nil) -> nil
app2(app2(filter, fun), app2(app2(cons, x), xs)) -> app2(app2(app2(app2(filter2, app2(fun, x)), fun), x), xs)
app2(app2(app2(app2(filter2, true), fun), x), xs) -> app2(app2(cons, x), app2(app2(filter, fun), xs))
app2(app2(app2(app2(filter2, false), fun), x), xs) -> app2(app2(filter, fun), xs)