Definition df-rmo 2516

Description: Define restricted "at most one". (Contributed by NM, 16-Jun-2017.)

Assertion

Ref	Expression
df-rmo	⊢ (∃*𝑥 ∈ 𝐴 𝜑 ↔ ∃*𝑥(𝑥 ∈ 𝐴 ∧ 𝜑))

Detailed syntax breakdown of Definition df-rmo

Step	Hyp	Ref	Expression
1		wph	. . 3 wff 𝜑
2		vx	. . 3 setvar 𝑥
3		cA	. . 3 class 𝐴
4	1, 2, 3	wrmo 2511	. 2 wff ∃*𝑥 ∈ 𝐴 𝜑
5	2	cv 1394	. . . . 5 class 𝑥
6	5, 3	wcel 2200	. . . 4 wff 𝑥 ∈ 𝐴
7	6, 1	wa 104	. . 3 wff (𝑥 ∈ 𝐴 ∧ 𝜑)
8	7, 2	wmo 2078	. 2 wff ∃*𝑥(𝑥 ∈ 𝐴 ∧ 𝜑)
9	4, 8	wb 105	1 wff (∃*𝑥 ∈ 𝐴 𝜑 ↔ ∃*𝑥(𝑥 ∈ 𝐴 ∧ 𝜑))

This definition is referenced by:  nfrmo1  2704  cbvrmow  2714  rmobida  2719  rmobiia  2722  rmoeq1f  2727  mormo  2748  reu5  2749  rmo5  2752  rmov  2820  rmo4  2996  rmo3f  3000  rmoan  3003  rmoim  3004  rmoimi2  3006  2reuswapdc  3007  2rmorex  3009  rmo2ilem  3119  rmo3  3121  rmob  3122  ssrmof  3287  dfdisj2  4060  dffun9  5346  fncnv  5386