This module contains theorems to be added to the @[method_specs_simp] simpset. When we use the
idiom of a heterogeneous class with notation (e.g. HAppend) and a homogeneous class that the user
typically instantiates, these rewrite the method specifications generated by @[method_specs] from
the homogeneous form to the desired heterogeneous form.
Should modules within Init use @[method_specs] on such instances, they should import this file.