Update type_inference.md

docs/type_inference.md

@@ -71,10 +71,11 @@ The solution is as follows:
    this isn't possible due to the inability to infer return types
    (such as with`ReshapeOp` or `BroadcastInDimOp`), create a verifier to
    contain the necessary verification logic. Typically inferable ops,
-   like `AddOp`, may still need a verifier to perform additional verifications
-   when quantization is involved.
+   like `AddOp`, may still need a verifier to perform additional verifications,
+   because they are verifying constraints of a provided return type, which
+   is not accessible in the type/shape inference methods.
 
-2. **For ops with regions** (like `ReduceOp/IfOp`; a full list is
+3. **For ops with regions** (like `ReduceOp/IfOp`; a full list is
    [here](https://github.com/openxla/stablehlo/pull/401)): The autogenerated
    builders don't take regions as parameters, so if these builders involve type
    inference, then the shape function will be called with empty regions (see