4JOHNTBALDWINANDALEXEIKOLESNIKOV2For2HdenotetheactionbyyxwheneveritisclearthatxandycomefromthesameHstalkSaythatyxIfIiscountablyinnitelet 1kbetheScottsentenceforthecountablyinniteL0 ID: 442179
4JOHNT.BALDWINANDALEXEIKOLESNIKOV(2)For2H denotetheactionbyy=x+