;; | ----------------------------------------------------------------------------
;; | GE_AdjacentPoly
;; | ----------------------------------------------------------------------------
;; | Function : Checks if two polyline entities or list of points meet at one
;; |            of their ends.
;; | Arguments:
;; |            'ename1'  - Overloaded argument (can be either a polyline
;; |                        object name or a vertex list of first polyline)
;; |            'ename2'  - Overloaded argument (can be either a polyline
;; |                        object name or a vertex list of second polyline)
;; | Action   : Returns the point where they meet or nil if they do not meet
;; | Updated  : February 12, 1999
;; | e-mail   : rakesh.rao@4d-technologies.com 
;; | Web      : www.4d-technologies.com
;; | ----------------------------------------------------------------------------


(defun GE_AdjacentPoly( ename1 ename2 / vlist1 vlist2 p1 t1 t2 t3 t4 )

(if (= (type ename1) 'ENAME)
(setq
	vlist1 (PL_plist ename1)
	vlist2 (PL_plist ename2)
)
(setq
	vlist1 ename1
	vlist2 ename2
))

(setq
	t1 (car vlist1)
	t2 (last vlist1)
	t3 (car vlist2)
	t4 (last vlist2)
	p1 nil
)

(cond
	((equal t1 t3 0.001)
		(setq p1 t1)
	)
	((equal t1 t4 0.001)
		(setq p1 t1)
	)
	((equal t2 t3 0.001)
		(setq p1 t2)
	)
	((equal t2 t4 0.001)
		(setq p1 t2)
	)
)
p1
)