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| author | Greg Brown <greg.brown01@ed.ac.uk> | 2023-06-30 20:45:33 +0100 |
|---|---|---|
| committer | Greg Brown <greg.brown01@ed.ac.uk> | 2023-06-30 20:45:33 +0100 |
| commit | 8c529393421843a7ccad041d2f29fa90b46bf6b6 (patch) | |
| tree | f7b31388e5ca5831ef84f9c9a6809a4eb77fa66b /src/Data/Fin/Occurs.idr | |
| parent | 621f6221048213dc4d359581197988050af99d0d (diff) | |
Define zippers and prove no cycles exist.
Diffstat (limited to 'src/Data/Fin/Occurs.idr')
| -rw-r--r-- | src/Data/Fin/Occurs.idr | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/src/Data/Fin/Occurs.idr b/src/Data/Fin/Occurs.idr index 74199d3..899e2a1 100644 --- a/src/Data/Fin/Occurs.idr +++ b/src/Data/Fin/Occurs.idr @@ -9,6 +9,7 @@ import Data.Maybe.Properties predInjective : {n : Nat} -> pred n = S k -> n = S (S k) predInjective {n = S n} prf = cong S prf +public export indexIsSuc : Fin n -> Exists (\k => n = S k) indexIsSuc FZ = Evidence _ Refl indexIsSuc (FS x) = Evidence _ Refl |