fact: Definition mapF : forall t:tag, {d:data | t=tagOf d} -> mapType t.
imports: JML(Prelude) Coq(ZArith) Coq(Bool) Coq(List) JML(TaggedList) JML(ListHelpers) JML(ListFunctions) JML(OptionHelpers) JML(JMLProgramPlusImpl) JML(JMLFull2Basic) JML(JMLExpressionNotations)