R
↳Dependency Pair Analysis
APP(app(map, f), app(app(cons, x), xs)) -> APP(app(cons, app(f, x)), app(app(map, f), xs))
APP(app(map, f), app(app(cons, x), xs)) -> APP(cons, app(f, x))
APP(app(map, f), app(app(cons, x), xs)) -> APP(f, x)
APP(app(map, f), app(app(cons, x), xs)) -> APP(app(map, f), xs)
APP(app(minus, app(s, x)), app(s, y)) -> APP(app(minus, app(p, app(s, x))), app(p, app(s, y)))
APP(app(minus, app(s, x)), app(s, y)) -> APP(minus, app(p, app(s, x)))
APP(app(minus, app(s, x)), app(s, y)) -> APP(p, app(s, x))
APP(app(minus, app(s, x)), app(s, y)) -> APP(p, app(s, y))
APP(app(div, app(s, x)), app(s, y)) -> APP(s, app(app(div, app(app(minus, x), y)), app(s, y)))
APP(app(div, app(s, x)), app(s, y)) -> APP(app(div, app(app(minus, x), y)), app(s, y))
APP(app(div, app(s, x)), app(s, y)) -> APP(div, app(app(minus, x), y))
APP(app(div, app(s, x)), app(s, y)) -> APP(app(minus, x), y)
APP(app(div, app(s, x)), app(s, y)) -> APP(minus, x)
R
↳DPs
→DP Problem 1
↳Rewriting Transformation
APP(app(div, app(s, x)), app(s, y)) -> APP(app(minus, x), y)
APP(app(div, app(s, x)), app(s, y)) -> APP(app(div, app(app(minus, x), y)), app(s, y))
APP(app(minus, app(s, x)), app(s, y)) -> APP(app(minus, app(p, app(s, x))), app(p, app(s, y)))
APP(app(map, f), app(app(cons, x), xs)) -> APP(app(map, f), xs)
APP(app(map, f), app(app(cons, x), xs)) -> APP(f, x)
APP(app(map, f), app(app(cons, x), xs)) -> APP(app(cons, app(f, x)), app(app(map, f), xs))
app(app(map, f), nil) -> nil
app(app(map, f), app(app(cons, x), xs)) -> app(app(cons, app(f, x)), app(app(map, f), xs))
app(app(minus, x), 0) -> x
app(app(minus, app(s, x)), app(s, y)) -> app(app(minus, app(p, app(s, x))), app(p, app(s, y)))
app(p, app(s, x)) -> x
app(app(div, 0), app(s, y)) -> 0
app(app(div, app(s, x)), app(s, y)) -> app(s, app(app(div, app(app(minus, x), y)), app(s, y)))
innermost
one new Dependency Pair is created:
APP(app(minus, app(s, x)), app(s, y)) -> APP(app(minus, app(p, app(s, x))), app(p, app(s, y)))
APP(app(minus, app(s, x)), app(s, y)) -> APP(app(minus, x), app(p, app(s, y)))
R
↳DPs
→DP Problem 1
↳Rw
→DP Problem 2
↳Rewriting Transformation
APP(app(minus, app(s, x)), app(s, y)) -> APP(app(minus, x), app(p, app(s, y)))
APP(app(div, app(s, x)), app(s, y)) -> APP(app(div, app(app(minus, x), y)), app(s, y))
APP(app(map, f), app(app(cons, x), xs)) -> APP(app(map, f), xs)
APP(app(map, f), app(app(cons, x), xs)) -> APP(f, x)
APP(app(map, f), app(app(cons, x), xs)) -> APP(app(cons, app(f, x)), app(app(map, f), xs))
APP(app(div, app(s, x)), app(s, y)) -> APP(app(minus, x), y)
app(app(map, f), nil) -> nil
app(app(map, f), app(app(cons, x), xs)) -> app(app(cons, app(f, x)), app(app(map, f), xs))
app(app(minus, x), 0) -> x
app(app(minus, app(s, x)), app(s, y)) -> app(app(minus, app(p, app(s, x))), app(p, app(s, y)))
app(p, app(s, x)) -> x
app(app(div, 0), app(s, y)) -> 0
app(app(div, app(s, x)), app(s, y)) -> app(s, app(app(div, app(app(minus, x), y)), app(s, y)))
innermost
one new Dependency Pair is created:
APP(app(minus, app(s, x)), app(s, y)) -> APP(app(minus, x), app(p, app(s, y)))
APP(app(minus, app(s, x)), app(s, y)) -> APP(app(minus, x), y)
R
↳DPs
→DP Problem 1
↳Rw
→DP Problem 2
↳Rw
...
→DP Problem 3
↳Narrowing Transformation
APP(app(minus, app(s, x)), app(s, y)) -> APP(app(minus, x), y)
APP(app(map, f), app(app(cons, x), xs)) -> APP(app(map, f), xs)
APP(app(map, f), app(app(cons, x), xs)) -> APP(f, x)
APP(app(map, f), app(app(cons, x), xs)) -> APP(app(cons, app(f, x)), app(app(map, f), xs))
APP(app(div, app(s, x)), app(s, y)) -> APP(app(minus, x), y)
APP(app(div, app(s, x)), app(s, y)) -> APP(app(div, app(app(minus, x), y)), app(s, y))
app(app(map, f), nil) -> nil
app(app(map, f), app(app(cons, x), xs)) -> app(app(cons, app(f, x)), app(app(map, f), xs))
app(app(minus, x), 0) -> x
app(app(minus, app(s, x)), app(s, y)) -> app(app(minus, app(p, app(s, x))), app(p, app(s, y)))
app(p, app(s, x)) -> x
app(app(div, 0), app(s, y)) -> 0
app(app(div, app(s, x)), app(s, y)) -> app(s, app(app(div, app(app(minus, x), y)), app(s, y)))
innermost
nine new Dependency Pairs are created:
APP(app(map, f), app(app(cons, x), xs)) -> APP(app(cons, app(f, x)), app(app(map, f), xs))
APP(app(map, app(map, f'')), app(app(cons, nil), xs)) -> APP(app(cons, nil), app(app(map, app(map, f'')), xs))
APP(app(map, app(map, f'')), app(app(cons, app(app(cons, x''), xs'')), xs)) -> APP(app(cons, app(app(cons, app(f'', x'')), app(app(map, f''), xs''))), app(app(map, app(map, f'')), xs))
APP(app(map, app(minus, x'')), app(app(cons, 0), xs)) -> APP(app(cons, x''), app(app(map, app(minus, x'')), xs))
APP(app(map, app(minus, app(s, x''))), app(app(cons, app(s, y')), xs)) -> APP(app(cons, app(app(minus, app(p, app(s, x''))), app(p, app(s, y')))), app(app(map, app(minus, app(s, x''))), xs))
APP(app(map, p), app(app(cons, app(s, x'')), xs)) -> APP(app(cons, x''), app(app(map, p), xs))
APP(app(map, app(div, 0)), app(app(cons, app(s, y')), xs)) -> APP(app(cons, 0), app(app(map, app(div, 0)), xs))
APP(app(map, app(div, app(s, x''))), app(app(cons, app(s, y')), xs)) -> APP(app(cons, app(s, app(app(div, app(app(minus, x''), y')), app(s, y')))), app(app(map, app(div, app(s, x''))), xs))
APP(app(map, f''), app(app(cons, x), nil)) -> APP(app(cons, app(f'', x)), nil)
APP(app(map, f''), app(app(cons, x), app(app(cons, x''), xs''))) -> APP(app(cons, app(f'', x)), app(app(cons, app(f'', x'')), app(app(map, f''), xs'')))
R
↳DPs
→DP Problem 1
↳Rw
→DP Problem 2
↳Rw
...
→DP Problem 4
↳Rewriting Transformation
APP(app(map, f''), app(app(cons, x), app(app(cons, x''), xs''))) -> APP(app(cons, app(f'', x)), app(app(cons, app(f'', x'')), app(app(map, f''), xs'')))
APP(app(map, app(div, app(s, x''))), app(app(cons, app(s, y')), xs)) -> APP(app(cons, app(s, app(app(div, app(app(minus, x''), y')), app(s, y')))), app(app(map, app(div, app(s, x''))), xs))
APP(app(map, app(div, 0)), app(app(cons, app(s, y')), xs)) -> APP(app(cons, 0), app(app(map, app(div, 0)), xs))
APP(app(map, p), app(app(cons, app(s, x'')), xs)) -> APP(app(cons, x''), app(app(map, p), xs))
APP(app(map, app(minus, app(s, x''))), app(app(cons, app(s, y')), xs)) -> APP(app(cons, app(app(minus, app(p, app(s, x''))), app(p, app(s, y')))), app(app(map, app(minus, app(s, x''))), xs))
APP(app(map, app(minus, x'')), app(app(cons, 0), xs)) -> APP(app(cons, x''), app(app(map, app(minus, x'')), xs))
APP(app(div, app(s, x)), app(s, y)) -> APP(app(minus, x), y)
APP(app(div, app(s, x)), app(s, y)) -> APP(app(div, app(app(minus, x), y)), app(s, y))
APP(app(map, app(map, f'')), app(app(cons, app(app(cons, x''), xs'')), xs)) -> APP(app(cons, app(app(cons, app(f'', x'')), app(app(map, f''), xs''))), app(app(map, app(map, f'')), xs))
APP(app(map, f), app(app(cons, x), xs)) -> APP(app(map, f), xs)
APP(app(map, f), app(app(cons, x), xs)) -> APP(f, x)
APP(app(minus, app(s, x)), app(s, y)) -> APP(app(minus, x), y)
app(app(map, f), nil) -> nil
app(app(map, f), app(app(cons, x), xs)) -> app(app(cons, app(f, x)), app(app(map, f), xs))
app(app(minus, x), 0) -> x
app(app(minus, app(s, x)), app(s, y)) -> app(app(minus, app(p, app(s, x))), app(p, app(s, y)))
app(p, app(s, x)) -> x
app(app(div, 0), app(s, y)) -> 0
app(app(div, app(s, x)), app(s, y)) -> app(s, app(app(div, app(app(minus, x), y)), app(s, y)))
innermost
one new Dependency Pair is created:
APP(app(map, app(minus, app(s, x''))), app(app(cons, app(s, y')), xs)) -> APP(app(cons, app(app(minus, app(p, app(s, x''))), app(p, app(s, y')))), app(app(map, app(minus, app(s, x''))), xs))
APP(app(map, app(minus, app(s, x''))), app(app(cons, app(s, y')), xs)) -> APP(app(cons, app(app(minus, x''), app(p, app(s, y')))), app(app(map, app(minus, app(s, x''))), xs))
R
↳DPs
→DP Problem 1
↳Rw
→DP Problem 2
↳Rw
...
→DP Problem 5
↳Rewriting Transformation
APP(app(map, app(minus, app(s, x''))), app(app(cons, app(s, y')), xs)) -> APP(app(cons, app(app(minus, x''), app(p, app(s, y')))), app(app(map, app(minus, app(s, x''))), xs))
APP(app(map, app(div, app(s, x''))), app(app(cons, app(s, y')), xs)) -> APP(app(cons, app(s, app(app(div, app(app(minus, x''), y')), app(s, y')))), app(app(map, app(div, app(s, x''))), xs))
APP(app(map, app(div, 0)), app(app(cons, app(s, y')), xs)) -> APP(app(cons, 0), app(app(map, app(div, 0)), xs))
APP(app(map, p), app(app(cons, app(s, x'')), xs)) -> APP(app(cons, x''), app(app(map, p), xs))
APP(app(map, app(minus, x'')), app(app(cons, 0), xs)) -> APP(app(cons, x''), app(app(map, app(minus, x'')), xs))
APP(app(minus, app(s, x)), app(s, y)) -> APP(app(minus, x), y)
APP(app(div, app(s, x)), app(s, y)) -> APP(app(minus, x), y)
APP(app(div, app(s, x)), app(s, y)) -> APP(app(div, app(app(minus, x), y)), app(s, y))
APP(app(map, app(map, f'')), app(app(cons, app(app(cons, x''), xs'')), xs)) -> APP(app(cons, app(app(cons, app(f'', x'')), app(app(map, f''), xs''))), app(app(map, app(map, f'')), xs))
APP(app(map, f), app(app(cons, x), xs)) -> APP(app(map, f), xs)
APP(app(map, f), app(app(cons, x), xs)) -> APP(f, x)
APP(app(map, f''), app(app(cons, x), app(app(cons, x''), xs''))) -> APP(app(cons, app(f'', x)), app(app(cons, app(f'', x'')), app(app(map, f''), xs'')))
app(app(map, f), nil) -> nil
app(app(map, f), app(app(cons, x), xs)) -> app(app(cons, app(f, x)), app(app(map, f), xs))
app(app(minus, x), 0) -> x
app(app(minus, app(s, x)), app(s, y)) -> app(app(minus, app(p, app(s, x))), app(p, app(s, y)))
app(p, app(s, x)) -> x
app(app(div, 0), app(s, y)) -> 0
app(app(div, app(s, x)), app(s, y)) -> app(s, app(app(div, app(app(minus, x), y)), app(s, y)))
innermost
one new Dependency Pair is created:
APP(app(map, app(minus, app(s, x''))), app(app(cons, app(s, y')), xs)) -> APP(app(cons, app(app(minus, x''), app(p, app(s, y')))), app(app(map, app(minus, app(s, x''))), xs))
APP(app(map, app(minus, app(s, x''))), app(app(cons, app(s, y')), xs)) -> APP(app(cons, app(app(minus, x''), y')), app(app(map, app(minus, app(s, x''))), xs))
R
↳DPs
→DP Problem 1
↳Rw
→DP Problem 2
↳Rw
...
→DP Problem 6
↳Narrowing Transformation
APP(app(map, app(minus, app(s, x''))), app(app(cons, app(s, y')), xs)) -> APP(app(cons, app(app(minus, x''), y')), app(app(map, app(minus, app(s, x''))), xs))
APP(app(map, f''), app(app(cons, x), app(app(cons, x''), xs''))) -> APP(app(cons, app(f'', x)), app(app(cons, app(f'', x'')), app(app(map, f''), xs'')))
APP(app(map, app(div, 0)), app(app(cons, app(s, y')), xs)) -> APP(app(cons, 0), app(app(map, app(div, 0)), xs))
APP(app(map, p), app(app(cons, app(s, x'')), xs)) -> APP(app(cons, x''), app(app(map, p), xs))
APP(app(map, app(minus, x'')), app(app(cons, 0), xs)) -> APP(app(cons, x''), app(app(map, app(minus, x'')), xs))
APP(app(minus, app(s, x)), app(s, y)) -> APP(app(minus, x), y)
APP(app(div, app(s, x)), app(s, y)) -> APP(app(minus, x), y)
APP(app(div, app(s, x)), app(s, y)) -> APP(app(div, app(app(minus, x), y)), app(s, y))
APP(app(map, app(map, f'')), app(app(cons, app(app(cons, x''), xs'')), xs)) -> APP(app(cons, app(app(cons, app(f'', x'')), app(app(map, f''), xs''))), app(app(map, app(map, f'')), xs))
APP(app(map, f), app(app(cons, x), xs)) -> APP(app(map, f), xs)
APP(app(map, f), app(app(cons, x), xs)) -> APP(f, x)
APP(app(map, app(div, app(s, x''))), app(app(cons, app(s, y')), xs)) -> APP(app(cons, app(s, app(app(div, app(app(minus, x''), y')), app(s, y')))), app(app(map, app(div, app(s, x''))), xs))
app(app(map, f), nil) -> nil
app(app(map, f), app(app(cons, x), xs)) -> app(app(cons, app(f, x)), app(app(map, f), xs))
app(app(minus, x), 0) -> x
app(app(minus, app(s, x)), app(s, y)) -> app(app(minus, app(p, app(s, x))), app(p, app(s, y)))
app(p, app(s, x)) -> x
app(app(div, 0), app(s, y)) -> 0
app(app(div, app(s, x)), app(s, y)) -> app(s, app(app(div, app(app(minus, x), y)), app(s, y)))
innermost
two new Dependency Pairs are created:
APP(app(div, app(s, x)), app(s, y)) -> APP(app(div, app(app(minus, x), y)), app(s, y))
APP(app(div, app(s, x'')), app(s, 0)) -> APP(app(div, x''), app(s, 0))
APP(app(div, app(s, app(s, x''))), app(s, app(s, y''))) -> APP(app(div, app(app(minus, app(p, app(s, x''))), app(p, app(s, y'')))), app(s, app(s, y'')))
R
↳DPs
→DP Problem 1
↳Rw
→DP Problem 2
↳Rw
...
→DP Problem 7
↳Rewriting Transformation
APP(app(div, app(s, app(s, x''))), app(s, app(s, y''))) -> APP(app(div, app(app(minus, app(p, app(s, x''))), app(p, app(s, y'')))), app(s, app(s, y'')))
APP(app(div, app(s, x'')), app(s, 0)) -> APP(app(div, x''), app(s, 0))
APP(app(map, f''), app(app(cons, x), app(app(cons, x''), xs''))) -> APP(app(cons, app(f'', x)), app(app(cons, app(f'', x'')), app(app(map, f''), xs'')))
APP(app(map, app(div, app(s, x''))), app(app(cons, app(s, y')), xs)) -> APP(app(cons, app(s, app(app(div, app(app(minus, x''), y')), app(s, y')))), app(app(map, app(div, app(s, x''))), xs))
APP(app(map, app(div, 0)), app(app(cons, app(s, y')), xs)) -> APP(app(cons, 0), app(app(map, app(div, 0)), xs))
APP(app(map, p), app(app(cons, app(s, x'')), xs)) -> APP(app(cons, x''), app(app(map, p), xs))
APP(app(map, app(minus, x'')), app(app(cons, 0), xs)) -> APP(app(cons, x''), app(app(map, app(minus, x'')), xs))
APP(app(minus, app(s, x)), app(s, y)) -> APP(app(minus, x), y)
APP(app(div, app(s, x)), app(s, y)) -> APP(app(minus, x), y)
APP(app(map, app(map, f'')), app(app(cons, app(app(cons, x''), xs'')), xs)) -> APP(app(cons, app(app(cons, app(f'', x'')), app(app(map, f''), xs''))), app(app(map, app(map, f'')), xs))
APP(app(map, f), app(app(cons, x), xs)) -> APP(app(map, f), xs)
APP(app(map, f), app(app(cons, x), xs)) -> APP(f, x)
APP(app(map, app(minus, app(s, x''))), app(app(cons, app(s, y')), xs)) -> APP(app(cons, app(app(minus, x''), y')), app(app(map, app(minus, app(s, x''))), xs))
app(app(map, f), nil) -> nil
app(app(map, f), app(app(cons, x), xs)) -> app(app(cons, app(f, x)), app(app(map, f), xs))
app(app(minus, x), 0) -> x
app(app(minus, app(s, x)), app(s, y)) -> app(app(minus, app(p, app(s, x))), app(p, app(s, y)))
app(p, app(s, x)) -> x
app(app(div, 0), app(s, y)) -> 0
app(app(div, app(s, x)), app(s, y)) -> app(s, app(app(div, app(app(minus, x), y)), app(s, y)))
innermost
one new Dependency Pair is created:
APP(app(div, app(s, app(s, x''))), app(s, app(s, y''))) -> APP(app(div, app(app(minus, app(p, app(s, x''))), app(p, app(s, y'')))), app(s, app(s, y'')))
APP(app(div, app(s, app(s, x''))), app(s, app(s, y''))) -> APP(app(div, app(app(minus, x''), app(p, app(s, y'')))), app(s, app(s, y'')))
R
↳DPs
→DP Problem 1
↳Rw
→DP Problem 2
↳Rw
...
→DP Problem 8
↳Rewriting Transformation
APP(app(div, app(s, app(s, x''))), app(s, app(s, y''))) -> APP(app(div, app(app(minus, x''), app(p, app(s, y'')))), app(s, app(s, y'')))
APP(app(map, app(minus, app(s, x''))), app(app(cons, app(s, y')), xs)) -> APP(app(cons, app(app(minus, x''), y')), app(app(map, app(minus, app(s, x''))), xs))
APP(app(map, f''), app(app(cons, x), app(app(cons, x''), xs''))) -> APP(app(cons, app(f'', x)), app(app(cons, app(f'', x'')), app(app(map, f''), xs'')))
APP(app(map, app(div, app(s, x''))), app(app(cons, app(s, y')), xs)) -> APP(app(cons, app(s, app(app(div, app(app(minus, x''), y')), app(s, y')))), app(app(map, app(div, app(s, x''))), xs))
APP(app(map, app(div, 0)), app(app(cons, app(s, y')), xs)) -> APP(app(cons, 0), app(app(map, app(div, 0)), xs))
APP(app(map, p), app(app(cons, app(s, x'')), xs)) -> APP(app(cons, x''), app(app(map, p), xs))
APP(app(map, app(minus, x'')), app(app(cons, 0), xs)) -> APP(app(cons, x''), app(app(map, app(minus, x'')), xs))
APP(app(minus, app(s, x)), app(s, y)) -> APP(app(minus, x), y)
APP(app(map, app(map, f'')), app(app(cons, app(app(cons, x''), xs'')), xs)) -> APP(app(cons, app(app(cons, app(f'', x'')), app(app(map, f''), xs''))), app(app(map, app(map, f'')), xs))
APP(app(map, f), app(app(cons, x), xs)) -> APP(app(map, f), xs)
APP(app(map, f), app(app(cons, x), xs)) -> APP(f, x)
APP(app(div, app(s, x)), app(s, y)) -> APP(app(minus, x), y)
APP(app(div, app(s, x'')), app(s, 0)) -> APP(app(div, x''), app(s, 0))
app(app(map, f), nil) -> nil
app(app(map, f), app(app(cons, x), xs)) -> app(app(cons, app(f, x)), app(app(map, f), xs))
app(app(minus, x), 0) -> x
app(app(minus, app(s, x)), app(s, y)) -> app(app(minus, app(p, app(s, x))), app(p, app(s, y)))
app(p, app(s, x)) -> x
app(app(div, 0), app(s, y)) -> 0
app(app(div, app(s, x)), app(s, y)) -> app(s, app(app(div, app(app(minus, x), y)), app(s, y)))
innermost
one new Dependency Pair is created:
APP(app(div, app(s, app(s, x''))), app(s, app(s, y''))) -> APP(app(div, app(app(minus, x''), app(p, app(s, y'')))), app(s, app(s, y'')))
APP(app(div, app(s, app(s, x''))), app(s, app(s, y''))) -> APP(app(div, app(app(minus, x''), y'')), app(s, app(s, y'')))
R
↳DPs
→DP Problem 1
↳Rw
→DP Problem 2
↳Rw
...
→DP Problem 9
↳Remaining Obligation(s)
APP(app(div, app(s, app(s, x''))), app(s, app(s, y''))) -> APP(app(div, app(app(minus, x''), y'')), app(s, app(s, y'')))
APP(app(div, app(s, x'')), app(s, 0)) -> APP(app(div, x''), app(s, 0))
APP(app(map, f''), app(app(cons, x), app(app(cons, x''), xs''))) -> APP(app(cons, app(f'', x)), app(app(cons, app(f'', x'')), app(app(map, f''), xs'')))
APP(app(map, app(div, app(s, x''))), app(app(cons, app(s, y')), xs)) -> APP(app(cons, app(s, app(app(div, app(app(minus, x''), y')), app(s, y')))), app(app(map, app(div, app(s, x''))), xs))
APP(app(map, app(div, 0)), app(app(cons, app(s, y')), xs)) -> APP(app(cons, 0), app(app(map, app(div, 0)), xs))
APP(app(map, p), app(app(cons, app(s, x'')), xs)) -> APP(app(cons, x''), app(app(map, p), xs))
APP(app(map, app(minus, x'')), app(app(cons, 0), xs)) -> APP(app(cons, x''), app(app(map, app(minus, x'')), xs))
APP(app(minus, app(s, x)), app(s, y)) -> APP(app(minus, x), y)
APP(app(div, app(s, x)), app(s, y)) -> APP(app(minus, x), y)
APP(app(map, app(map, f'')), app(app(cons, app(app(cons, x''), xs'')), xs)) -> APP(app(cons, app(app(cons, app(f'', x'')), app(app(map, f''), xs''))), app(app(map, app(map, f'')), xs))
APP(app(map, f), app(app(cons, x), xs)) -> APP(app(map, f), xs)
APP(app(map, f), app(app(cons, x), xs)) -> APP(f, x)
APP(app(map, app(minus, app(s, x''))), app(app(cons, app(s, y')), xs)) -> APP(app(cons, app(app(minus, x''), y')), app(app(map, app(minus, app(s, x''))), xs))
app(app(map, f), nil) -> nil
app(app(map, f), app(app(cons, x), xs)) -> app(app(cons, app(f, x)), app(app(map, f), xs))
app(app(minus, x), 0) -> x
app(app(minus, app(s, x)), app(s, y)) -> app(app(minus, app(p, app(s, x))), app(p, app(s, y)))
app(p, app(s, x)) -> x
app(app(div, 0), app(s, y)) -> 0
app(app(div, app(s, x)), app(s, y)) -> app(s, app(app(div, app(app(minus, x), y)), app(s, y)))
innermost