import Unify ( tcMatchTys, tcMatchTyX )
import Util ( zipLazy, isSingleton, notNull, sortLe )
import List ( partition, elemIndex )
import SrcLoc ( Located(..), unLoc, getLoc, srcLocSpan )
import ListSetOps ( equivClasses, minusList )
import Unify ( tcMatchTys, tcMatchTyX )
import Util ( zipLazy, isSingleton, notNull, sortLe )
import List ( partition, elemIndex )
import SrcLoc ( Located(..), unLoc, getLoc, srcLocSpan )
import ListSetOps ( equivClasses, minusList )