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authorGreg Brown <greg.brown01@ed.ac.uk>2023-07-10 13:37:56 +0100
committerGreg Brown <greg.brown01@ed.ac.uk>2023-07-10 13:37:56 +0100
commitce546fe96974cb7aa3b09c729f33ac6ba5169299 (patch)
treed58a1a217c54ae07aefb1f6b5c886e64c6b051db /src/Data/Maybe/Properties.idr
parent849b99d0a51674a15acfdfe4b6f6606491b20166 (diff)
Describe unification.
Diffstat (limited to 'src/Data/Maybe/Properties.idr')
-rw-r--r--src/Data/Maybe/Properties.idr5
1 files changed, 5 insertions, 0 deletions
diff --git a/src/Data/Maybe/Properties.idr b/src/Data/Maybe/Properties.idr
index 99a3507..459cb8f 100644
--- a/src/Data/Maybe/Properties.idr
+++ b/src/Data/Maybe/Properties.idr
@@ -20,6 +20,11 @@ extractIsJust ItIsJust = (_ ** Refl)
%inline
export
+extractIsNothing : {x : Maybe a} -> (0 _ : IsNothing x) -> x = Nothing
+extractIsNothing ItIsNothing = Refl
+
+%inline
+export
mapIsJust : (0 f : a -> b) -> IsJust x -> IsJust (map f x)
mapIsJust f ItIsJust = ItIsJust