Propositions express in the last resort the relation of predicate or predicates to a subject, and this Leibnitz holds after considering the case of **relational** propositions where either term may hold the position of grammatical subject, A = B and the like.

There is a formal-symbolic logic engaged with the elaboration of a **relational** calculus.

The view of inference with which he complements it is only less satisfactory because of a failure to distinguish the principle of nexus in syllogism from its traditional formulation and rules, and because he is hampered by the intractability which he finds in certain forms of **relational** construction.