subtyping.md: typo fix

diff --git a/src/doc/nomicon/subtyping.md b/src/doc/nomicon/subtyping.md
index 5def5c3903353ef85575993ccaa6c0173db1b316..eb940e811a4fa13f30d55ef44272b9add7b38b4a 100644 (file)
--- a/src/doc/nomicon/subtyping.md
+++ b/src/doc/nomicon/subtyping.md
@@ -53,7 +53,7 @@ inferred variance, so `Fn(T)` is invariant in `T`).
 Some important variances:
 
 * `&'a T` is variant over `'a` and `T` (as is `*const T` by metaphor)
-* `&'a mut T` is variant with over `'a` but invariant over `T`
+* `&'a mut T` is variant over `'a` but invariant over `T`
 * `Fn(T) -> U` is invariant over `T`, but variant over `U`
 * `Box`, `Vec`, and all other collections are variant over the types of
   their contents