Add a law about endpoints

haskell · Jan 18, 2021 · a663ea0 · a663ea0
1 parent 3278904
commit a663ea0
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/src/System/Random/Internal.hs b/src/System/Random/Internal.hs
@@ -621,6 +621,11 @@ class UniformRange a where
   --
   -- > isInRange (x, x) y == x == y
   --
+  -- Endpoints are endpoints:
+  --
+  -- > isInRange (lo, hi) x ==>
+  -- > isInRange (lo, x) hi == x == hi
+  --
   -- Ranges are transitive relations:
   --
   -- > isInRange (lo, hi) lo' && isInRange (lo, hi) hi' &&