We continue studying the properties of the f -index of inclusion and show that, given a fixed pair of fuzzy sets, their f -index
of inclusion can be linked to a fuzzy conjunction which is part of an adjoint pair. We also show that, when this pair is used as
the underlying structure to provide a fuzzy interpretation of the modus ponens inference rule, it provides the maximum possible
truth-value in the conclusion among all those values obtained by fuzzy modus ponens using any other possible adjoint pair.
