;; | ----------------------------------------------------------------------------
;; | GE_TnLine2Arc
;; | ----------------------------------------------------------------------------
;; | Function : Checks for tangency between a line and arc segment
;; | Arguments: 'CenPt1' - Center point of arc
;; |            'p1'     - First point of arc
;; |            'p2'     - End point of arc
;; |            'p3'     - First point of line
;; |            'p4'     - End point of line
;; |             FUZZ    - Tolerance within which to check for tangency
;; | Returns  : 'T' or 'nil' - Depending on whether the line and arc are tangents
;; | Updated  : December 2, 1999
;; | e-mail   : rakesh.rao@4d-technologies.com 
;; | Web      : www.4d-technologies.com
;; | ----------------------------------------------------------------------------


(defun GE_TnLine2Arc(CenPt1 p1 p2 p3 p4 FUZZ / a1 a2 Tang)

(setq
	a1   (GE_AngleBetn2L CenPt1 p1 p3 p4)
	a2   (GE_AngleBetn2L CenPt1 p2 p3 p4)
	a1   (append a1 a2)
	Tang nil
)
(foreach a2 a1
	(if (<= (abs (- a2 90.0)) FUZZ)
		(setq Tang T)
	)
)
Tang
)