diff --git a/core/mathx/range.go b/core/mathx/range.go
index 17e63fd5f..8b2574c51 100644
--- a/core/mathx/range.go
+++ b/core/mathx/range.go
@@ -1,5 +1,6 @@
 package mathx
 
+// Numerical is a constraint that permits any numeric type.
 type Numerical interface {
 	~int | ~int8 | ~int16 | ~int32 | ~int64 |
 		~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 |