#### 6.1.2.6 The for-as-on-list subclause ¶

In the for-as-on-list subclause, the `for` or `as` construct iterates over a list. It checks for the end of the list as if by using atom.

The variable var is bound to the successive tails of the list in form1. At the end of each iteration, the function step-fun is applied to the list; the default value for step-fun is cdr. The loop keywords `on` and `by` serve as valid prepositions in this syntax. The `for` or `as` construct causes termination when the end of the list is reached.