Recent investigations show a remarkable convergence among contemporary unification-based formalisms for syntactic description. This convergence is now i t s e l f becoming an object of study, and there is an increasing recognition of the need for e x p l i c i t characterizations of the properties that relate and distinguish similar grammar formalisms. The paper proposes a series of changes in the formalism of Generalized Phrase Structure Grammar that throw light on its relation to Functional Unification Grammar. The essential contribution is a generalization of cooccurrence restrictions, which become the principal and unifying device.
