Definition df-base 13360

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 13354	. 2 class Base
2		c1 8180	. . 3 class 1
3	2	cslot 13353	. 2 class Slot 1
4	1, 3	wceq 1402	1 wff Base = Slot 1

This definition is used by:  base0  13404  baseval  13407  baseid  13408  basendx  13409  basendxnn  13410  basendxnplusgndx  13481  basendxnmulrndx  13490