Definition df-dm 3269

Description: Define the domain of a class. Definition 3 of [Suppes] p. 59.

Assertion

Ref	Expression
df-dm	⊢ dom A = {x∣∃y xAy}

Distinct variable group:   x,y,A

Detailed syntax breakdown of Definition df-dm

Step	Hyp	Ref	Expression
1		cA	. . 3 class A
2	1	cdm 3251	. 2 class dom A
3		vx	. . . . . 6 set x
4	3	cv 991	. . . . 5 class x
5		vy	. . . . . 6 set y
6	5	cv 991	. . . . 5 class y
7	4, 6, 1	wbr 2692	. . . 4 wff xAy
8	7, 5	wex 1016	. . 3 wff ∃y xAy
9	8, 3	cab 1505	. 2 class {x∣∃y xAy}
10	2, 9	wceq 992	1 wff dom A = {x∣∃y xAy}

This definition is referenced by:  dfdm3 3393  dfrn2 3394  dfdm4 3396  eldm 3398  dmi 3415  dm0rn0 3417  dmcoss 3450  domleqt 10792

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