Definition df-lng

Description: Define the line index extractor for geometries. (Contributed by Thierry Arnoux, 27-Mar-2019) Use its index-independent form lngid instead. (New usage is discouraged.)

	Ref	Expression
Assertion	df-lng	|- LineG = Slot ; 1 7

Detailed syntax breakdown

Step	Hyp	Ref	Expression
0		clng	|- LineG
1		c1	|- 1
2		c7	|- 7
3	1 2	cdc	|- ; 1 7
4	3	cslot	|- Slot ; 1 7
5	0 4	wceq	|- LineG = Slot ; 1 7