Define indexed function types.

1 files changed, 10 insertions, 0 deletions

diff --git a/src/Soat/Relation.idr b/src/Soat/Relation.idr
index 9a394c2..cb94216 100644
--- a/src/Soat/Relation.idr
+++ b/src/Soat/Relation.idr
@@ -73,3 +73,13 @@ record ISetoid (a : Type) where
   0 U         : a -> Type
   0 relation  : IRel U
   equivalence : IEquivalence U relation
+
+public export
+IFunc : {a : Type} -> (x, y : a -> Type) -> Type
+IFunc {a} x y = (i : a) -> x i -> y i
+
+public export
+record IFunction {a : Type} (x, y : ISetoid a) where
+  constructor MkIFunction
+  func : IFunc x.U y.U
+  cong : (i : a) -> {u, v : x.U i} -> x.relation i u v -> y.relation i (func i u) (func i v)