sembr

Author: tshepang

src/ty-fold.md

@@ -1,8 +1,10 @@
 # `TypeFoldable` and `TypeFolder`
 
-In [a previous chapter], we discussed instantiating binders. This involves looking at everything inside of a `Early(Binder)`
-to find any usages of the bound vars in order to replace them. Binders can wrap an arbitrary Rust type `T`, not just a `Ty`. So,
-how do we implement the `instantiate` methods on the `Early/Binder` types.
+In [a previous chapter], we discussed instantiating binders.
+This involves looking at everything inside of a `Early(Binder)`
+to find any usages of the bound vars in order to replace them.
+Binders can wrap an arbitrary Rust type `T`, not just a `Ty`.
+So, how do we implement the `instantiate` methods on the `Early/Binder` types.
 
 The answer is a couple of traits:
 [`TypeFoldable`](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/fold/trait.TypeFoldable.html)