There is little that needs to be said about this procedure in addition to the author’s comment. This procedure is called by
access (6754) ialloc (7072) alloc (6961) ifree (7138) free (7004) iupdat (7383)
Note the cunning use of “n1”, “n2” which are declared as character pointers i.e. as unsigned integers. This allows only one sided tests on the two variables at line 7177.