typo

proposals/span-safety.md

@@ -74,7 +74,7 @@ Another way to look at this is that writeable references to a ref-like variable
 
 - ref-like types must be readonly. 
 
-This is basically follows from the previous "only pass by read-only references" rule when applied to "this" inside members of ref-like types.
+This basically follows from the previous "only pass by read-only references" rule when applied to "this" inside members of ref-like types.
 
 ## not all `ref-like` variables are safe to return. ##