1878	 Recovery of Reentrant List Structures in SLIP	 One consequence of the reference-count-based space-recovery system employed by SLIP is that reentrant list structures are not recovered even when explicitly erased. LISP-like garbage-collection schemes are free of this impediment. They however depend on being able to find and mark nodes that are reachable from program variables. By tracing all descendants from program variables may then be identified and collected. The list-creating function LIST of SLIP may be amended to mark those lists for which the programmer wishes to assume responsibility. Given this modification a LISP-like garbage collector that recovers abandoned reentrant list structures may then be appended to the SLIP system. list processing SLIP garbage-collection
