These exercises combine left-hand finger independence with slurs: some fingers must hold notes while others perform slurs continuously. The fingers not performing the slurs are also required to move to form other notes . These exercises help create mental and physical independence. As one of Chopin's most important pupils put it, "It is not the exercise, per se, that one practices, but the development of the hand by means of it." For advanced guitarists.
You'll get a two-page PDF with some challenging left-hand exercise for classical guitarists.