Sag and colleagues designed MRS to meet the competing demands of expressive adequacy, grammatical compatibility, computational tractability, and underspecifiability.
it is a computational semantic formalism that allows grammars like the English Resource Grammar to make explicit exactly as much information about semantic predicate argument structure and quantifier and operator scope as is determined by sentence structure, leaving further ambiguity represented via underspecification rather than enumeration of, for example, the full set of possible quantifier scopings for each item.