mirror of
https://github.com/idris-lang/Idris2.git
synced 2024-12-20 18:21:47 +03:00
26 lines
594 B
Idris
26 lines
594 B
Idris
|
module Issue893
|
||
|
|
|
||
|
|
%default total
|
||
|
|
|
||
|
|
foo : (a, b : Nat) -> Bool
|
||
|
|
foo Z b = False
|
||
|
|
foo (S _) b = False
|
||
|
|
|
||
|
|
notFoo : (a, b : Nat) -> Not (foo a b = True)
|
||
|
|
notFoo Z _ = uninhabited
|
||
|
|
notFoo (S _) _ = uninhabited
|
||
|
|
|
||
|
|
bar : (a, b : Nat) -> (foo a b) && c = foo a b
|
||
|
|
bar a b with (foo a b) proof ab
|
||
|
|
bar a b | True = absurd $ notFoo a b ab
|
||
|
|
bar a b | False = Refl
|
||
|
|
|
||
|
|
goo : (a, b : Nat) -> Bool -> Bool
|
||
|
|
goo a b True = True
|
||
|
|
goo a b False = foo a b || foo a b
|
||
|
|
|
||
|
|
bar2 : (a, b : Nat) -> goo a b (foo a b) = foo a b
|
||
|
|
bar2 a b with (foo a b) proof ab
|
||
|
|
bar2 a b | True = Refl
|
||
|
|
bar2 a b | False = rewrite ab in Refl
|