Definition df-dom 3275

Description: Define dominance relation. For an alternate definition see dfdom2 3288. Compare Definition of [Enderton] p. 145. Typical textbook definitions are derived as brdom 3283 and domen 3284.

Assertion

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

Distinct variable group(s):   x,y,f

Detailed syntax breakdown of Definition df-dom

Step	Hyp	Ref	Expression
1		cdom 3272	. 2 class ≼
2		vx	. . . . . 6 set x
3	2	cv 1089	. . . . 5 class x
4		vy	. . . . . 6 set y
5	4	cv 1089	. . . . 5 class y
6		vf	. . . . . 6 set f
7	6	cv 1089	. . . . 5 class f
8	3, 5, 7	wf1 2419	. . . 4 wff f:x–1-1→y
9	8, 6	wex 678	. . 3 wff ∃f f:x–1-1→y
10	9, 2, 4	copab 2055	. 2 class {⟨x, y⟩∣∃f f:x–1-1→y}
11	1, 10	wceq 1091	1 wff ≼ = {⟨x, y⟩∣∃f f:x–1-1→y}

This definition is referenced by:  reldom 3278  brdomg 3281  enssdom 3287

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