exprIsHNF (Type ty) = True -- Types are honorary Values;
-- we don't mind copying them
exprIsHNF (Lam b e) = isRuntimeVar b || exprIsHNF e
exprIsHNF (Type ty) = True -- Types are honorary Values;
-- we don't mind copying them
exprIsHNF (Lam b e) = isRuntimeVar b || exprIsHNF e