We study translations of dyadic first-order sentences into equalities between relationalexpressions. The proposed translation techniques (which work also in the conversedirection) exploit a graphical representation of formulae in a hybrid of the twoformalisms. A major enhancement relative to previous work is that we can cope with therelational complement construct and with the negation connective. Complementation ishandled by adopting a Smullyan-like uniform notation to classify and decompose relationalexpressions; negation is treated by means of a generalized graph-representation offormulae in ℒ+, and through a series of graph-transformation rules whichreflect the meaning of connectives and quantifiers.
