;; | ----------------------------------------------------------------------------
;; | GE_TnLine2Line
;; | ----------------------------------------------------------------------------
;; | Function : Checks for tangency between a line and a line
;; | Arguments:
;; |            'p1'     - Start point of first line
;; |            'p2'     - End point of first line
;; |            'p3'     - Start point of second line
;; |            'p4'     - End point of second line
;; |             FUZZ    - Tolerance within which to check for tangency
;; | Returns  : 'T' or 'nil' - Depending on whether the two line segments are tangents
;; |            (collinear)
;; | Updated  : December 18 2000
;; | e-mail   : rakesh.rao@4d-technologies.com 
;; | Web      : www.4d-technologies.com
;; | ----------------------------------------------------------------------------


(defun GE_TnLine2Line(p1 p2 p3 p4 FUZZ / Lst)

(setq Lst (LI_MakeUnique (list p1 p2 p3 p4)))
(if (= (length Lst) 3)
	(if (GE_Collinear? (nth 0 Lst) (nth 1 Lst) (nth 2 Lst) nil FUZZ)
		T
		nil
	)
	nil
)
)