We introduce a first-order language for semantic underspecification that we call Constraint Language for Lambda-Structures (CLLS). A Astructure can be considered as a A-term up to consistent renaming of bound variables (aequality); a constraint of CLLS is an underspecified description of a A-structure. CLLS solves a capturing problem omnipresent in underspecified scope representations. CLLS features constraints for dominance, lambda binding, parallelism, and anaphoric links. Based on CLLS we present a simple, integrated, and underspecified treatment of scope, parallelism, and anaphora.