Definition df-base 13004

Description: Define the base set (also called underlying set, ground set, carrier set, or carrier) extractor for extensible structures. (Contributed by NM, 4-Sep-2011.) (Revised by Mario Carneiro, 14-Aug-2015.)

Assertion

Ref	Expression
df-base	⊢ Base = Slot 1

Detailed syntax breakdown of Definition df-base

Step	Hyp	Ref	Expression
1		cbs 12998	. 2 class Base
2		c1 7968	. . 3 class 1
3	2	cslot 12997	. 2 class Slot 1
4	1, 3	wceq 1375	1 wff Base = Slot 1

This definition is referenced by:  base0  13048  baseval  13051  baseid  13052  basendx  13053  basendxnn  13054  basendxnplusgndx  13124  basendxnmulrndx  13133