Reducing sup-t-norm and inf-residuum to a single type of fuzzy relational equations

We show that the sup-t-norm and inf-residuum types of fuzzy relational equations, considered in the literature as two different types, can be viewed as two particular instances of a single, more general type of equation. We demonstrate that several pairs of corresponding results on the sup-t-norm and inf-residuum types of equations are simple consequences of single results on the on the more general type of equation.