syntax for higher-order functors (additions and changes) I 2 Int = FunIntEnv \Theta StrIntEnv \Theta Fin(var) SIE 2 StrIntEnv = strid fin ! Int FIE 2 FunIntEnv = funid fin ! Int IB 2 IntBasis = FunIntEnv \Theta SigEnv \Theta StrIntEnv ME 2 ModEnv = FunEnv \Theta ModStrEnv \Theta VarEnv MSE 2 ModStrEnv = strid fin ! ModEnv B 2 Basis = SigEnv \Theta ModEnv FIGURE 5. Semantic objects for higher-order functors (additions and changes) thinning functors. The nature of this information is discussed at length later. Interface Bases (IntBasis) These now have a new component: a functor interface environment. Module-level environments (ModEnv) These are the environments obtained as the result of evaluating structures. Since structures can contain functors, these environments contain a functor environment (FunEnv) component. In the rest of this paper we will refer to these objects as "environments" unless there is a possibility of confusion with Core-level environments. Module-lev...