;; | -----------------------------------------------------------------------------
;; | SS_SSsub
;; | -----------------------------------------------------------------------------
;; | Function : Subtracts one selection set from another and returns their
;; |            difference
;; | Arguments:
;; |            'ss1'    - First Selection set (to subtract from)
;; |            'ss2'    - Second Seclection set (to be subtracted)
;; | Return   : The difference selection set
;; | Updated  : April 24, 1998
;; | e-mail   : rakesh.rao@4d-technologies.com 
;; | Web      : www.4d-technologies.com
;; | -----------------------------------------------------------------------------


(defun SS_SSsub(ss1 ss2 / ss)

(cond
	((and ss1 ss2)
		(command "._Select" ss1 "_Remove" ss2 "")
		(setq ss (ssget "_P"))
	)
	((and ss1 (not ss2))
		(setq ss ss1)
	)
	(T
		(setq ss nil)
	)
)
ss
)