Update the specs

Author: natsukagami

docs/_docs/reference/experimental/erased-defs-spec.md

@@ -66,5 +66,5 @@ TODO: complete
 
 
 8. Type Restrictions
-   * `erased` vals and defs are limited to realizable types, that is, types that are inhabited by non-null values.
-     This restriction stops us from creating an uninhabited erased value, which leads to unsoundness in type-checking (see #4060).
+   * For dependent functions, `erased` parameters are limited to realizable types, that is, types that are inhabited by non-null values.
+     This restriction stops us from using a bad bound introduced by an erased value, which leads to unsoundness (see #4060).