Counterexampleisanexamplethatisusedtodisproveastatement,itprovesthatastatementisnotALWAYStrue,butitcannotproveastatementisNEVERtrue.
Hereisanexample:'Theoppositeofanumberisalwayspositive.'
Counterexamplefortheabovestatement:Theoppositeof2is-2,anegativenumber.ButasIsaid,thiscounterexamplecannotproveabovestatementisNEVERtrue-Theoppositeof-2is2,whichistrue.