tyVarsOfType, tyVarsOfTypes, tyVarsOfTheta, applyTys,
mkForAllTys, boxedTypeKind
)
-import PprType ( {- instance Outputable Type -} )
import Subst ( Subst, mkSubst, substTy, mkSubst, substBndrs, extendSubstList,
substId, substAndCloneId, substAndCloneIds, lookupIdSubst, substInScope
)