Definition df-lng 28928

Description: Define the line index extractor for geometries. (Contributed by Thierry Arnoux, 27-Mar-2019.) Use its index-independent form lngid 28932 instead. (New usage is discouraged.)

Assertion

Ref	Expression
df-lng	⊢ LineG = Slot ;17

Detailed syntax breakdown of Definition df-lng

Step	Hyp	Ref	Expression
1		clng 28926	. 2 class LineG
2		c1 11228	. . . 4 class 1
3		c7 12429	. . . 4 class 7
4	2, 3	cdc 12841	. . 3 class ;17
5	4	cslot 17388	. 2 class Slot ;17
6	1, 5	wceq 1570	1 wff LineG = Slot ;17

This definition is used by:  lngndx  28930  lngid  28932