Abstract out "sets of definitions" so that they could potentially be used in `where` clauses.
Abstract out "sets of definitions" so that they could potentially be used in `where` clauses.

laszlopandy/elm-compiler,mgold/Elm,5outh/Elm,Axure/elm-compiler,pairyo/elm-compiler,JoeyEremondi/elm-pattern-effects,deadfoxygrandpa/Elm