It is not entirely clear what "inheriting" base class functions means here. It could refer to:

• Inheriting member functions through a using-declaration.
• Operator overloads of base classes being looked up.

Judging from the context, I think it refers to the latter. This edit clarifies that by adding a reference to [class.member.lookup].

I also find "base class functions" a little bit unconventional. We probably want to say "member functions" here.