Exactly this is how i need List 1 = ((0 0) (1 0.1) (2 0.1) (3 0.1) (4 0.2) (5 0.2) (6 0.3) (7 0.3))

First of all the list given above can vary every time secondly i want to seprate the list for same cdr elements and store them to a variable Like i want like this and all the List with similar cdr element and make a list which contain all these values.
thanks

List A = (0 0)

List B = (1 0.1) (2 0.1)(3 0.1)

List C = ............................etc

Thanks