skewness of two linesskewness positiveskiddingskipskip hoistskip lots sampling planslabslackslack timeslack variableslacknessslackness conditions complementaryslackness theorem complementaryslagslag pocketslag postslaggingslantslant heightslant lineslant productslanting fraction lineslanting upwardslantwiseslashslat conveyorslat elevatorsleepest slopesliceslide fictureslide fitslide frame sawslide ruleslide valvesliderslidingsliding barsliding vectorslightlyslip gaugeslip planceslipline gageslitslit domainslitterslittingslitting attachmentslobbovian integralslopeslope angle