The subtle case is one where the literal sense is still actively used, but a conventional figurative sense is also familiar. The disagreement concerns which interpretation takes precedence in such a case.
«ولو كان لها مجاز متعارف فالحقيقة أولى عند أبي حنيفة»
If a conventional figurative sense also exists, Abu Hanifa gives precedence to the literal sense.
The book presents Abu Hanifa as preferring the literal sense, while Abu Yusuf and Muhammad may prefer the general scope of the established figurative usage. This is a methodological difference, not a claim that any sentence automatically includes every possible meaning.