import Subst ( Subst, InScopeSet, mkInScopeSet, lookupSubst, extendSubst,
substEnv, setSubstEnv, emptySubst, isInScope, emptyInScopeSet,
bindSubstList, unBindSubstList, substInScope, uniqAway
import Subst ( Subst, InScopeSet, mkInScopeSet, lookupSubst, extendSubst,
substEnv, setSubstEnv, emptySubst, isInScope, emptyInScopeSet,
bindSubstList, unBindSubstList, substInScope, uniqAway