The unity of the proposition is the new, budding topic in the paradigm of structured meaning. This paradigm is establishing itself as the successor of the fruitful, but insufficient paradigm of possible-world semantics. The unity problem is to explain how several entities, at least an individual A and a property F, combine into one entity, the structured proposition P that A is an F, and what associates P with the truth-condition that is satisfied exactly when A is an F. The transition between paradigms marks a transition from the set theory of model-theoretic semantics to the part/whole theory (mereology) of structured meanings. One unsettled question is how fine-grained (how hyperintensional) structured propositions must be to serve as sentential meanings and objects of attitudes. Another is the unity problem, which is only now beginning to receive its due attention in contemporary semantic theory. The objective of my research is a solution that is both philosophically and logically adequate. The objective will be achieved through the methodology of philosophical logic, which applies logical techniques to philosophical problems. My theoretical framework is a procedural semantics construing propositions as structured procedures whose parts are sub-procedures and whose unifier is the procedure of predicating a property of an individual. The proposed research is continuous with my decade-long track record of published research on structured meaning, hyperintensional logic, and procedural semantics. The relevance and urgency of this research is to fill a big gap in the paradigm of structured meaning so as to advance philosophical logic, philosophy of language, and the theoretical foundations of computer science and programming languages. The research facility of LOGOS at University of Barcelona is the ideal location: it is one of the most dynamic, internationally oriented, and prominent research institutions in philosophical logic and analytic philosophy worldwide.