Definition df-dom 6246

Description: Define the dominance relation. Compare Definition of [Enderton] p. 145. Typical textbook definitions are derived as brdom 6254 and domen 6255. (Contributed by NM, 28-Mar-1998.)

Assertion

Ref	Expression
df-dom	⊢ ≼ = {⟨𝑥, 𝑦⟩ ∣ ∃𝑓 𝑓:𝑥–1-1→𝑦}

Distinct variable group:   𝑥,𝑦,𝑓

Detailed syntax breakdown of Definition df-dom

Step	Hyp	Ref	Expression
1		cdom 6243	. 2 class ≼
2		vx	. . . . . 6 setvar 𝑥
3	2	cv 1283	. . . . 5 class 𝑥
4		vy	. . . . . 6 setvar 𝑦
5	4	cv 1283	. . . . 5 class 𝑦
6		vf	. . . . . 6 setvar 𝑓
7	6	cv 1283	. . . . 5 class 𝑓
8	3, 5, 7	wf1 4919	. . . 4 wff 𝑓:𝑥–1-1→𝑦
9	8, 6	wex 1421	. . 3 wff ∃𝑓 𝑓:𝑥–1-1→𝑦
10	9, 2, 4	copab 3838	. 2 class {⟨𝑥, 𝑦⟩ ∣ ∃𝑓 𝑓:𝑥–1-1→𝑦}
11	1, 10	wceq 1284	1 wff ≼ = {⟨𝑥, 𝑦⟩ ∣ ∃𝑓 𝑓:𝑥–1-1→𝑦}

This definition is referenced by:  reldom  6249  brdomg  6252  enssdom  6265