Source : WordNet®

logical relation
     n : a relation between propositions

Source : Free On-Line Dictionary of Computing

logical relation
     
        A {relation} R satisfying
     
        f R g  <=>  For all a, b,  a R b => f a R g b
     
        This definition, by Plotkin, can be used to extend the
        definition of a relation on the types of a and b to a relation
        on functions.