Theorem pw1m 7485

Description: A truth value which is inhabited is equal to true. This is a variation of pwntru 4295 and pwtrufal 16702. (Contributed by Jim Kingdon, 10-Jan-2026.)

Assertion

Ref	Expression
pw1m	⊢ ((𝐴 ∈ 𝒫 1o ∧ ∃𝑥 𝑥 ∈ 𝐴) → 𝐴 = 1o)

Distinct variable group:   𝑥,𝐴

Proof of Theorem pw1m

Step	Hyp	Ref	Expression
1		elpwi 3665	. . . . . . . 8 ⊢ (𝐴 ∈ 𝒫 1o → 𝐴 ⊆ 1o)
2		df1o2 6639	. . . . . . . 8 ⊢ 1o = {∅}
3	1, 2	sseqtrdi 3276	. . . . . . 7 ⊢ (𝐴 ∈ 𝒫 1o → 𝐴 ⊆ {∅})
4	3	adantr 276	. . . . . 6 ⊢ ((𝐴 ∈ 𝒫 1o ∧ 𝑥 ∈ 𝐴) → 𝐴 ⊆ {∅})
5	1	sselda 3228	. . . . . . . . . 10 ⊢ ((𝐴 ∈ 𝒫 1o ∧ 𝑥 ∈ 𝐴) → 𝑥 ∈ 1o)
6	5, 2	eleqtrdi 2324	. . . . . . . . 9 ⊢ ((𝐴 ∈ 𝒫 1o ∧ 𝑥 ∈ 𝐴) → 𝑥 ∈ {∅})
7		elsni 3691	. . . . . . . . 9 ⊢ (𝑥 ∈ {∅} → 𝑥 = ∅)
8	6, 7	syl 14	. . . . . . . 8 ⊢ ((𝐴 ∈ 𝒫 1o ∧ 𝑥 ∈ 𝐴) → 𝑥 = ∅)
9		simpr 110	. . . . . . . 8 ⊢ ((𝐴 ∈ 𝒫 1o ∧ 𝑥 ∈ 𝐴) → 𝑥 ∈ 𝐴)
10	8, 9	eqeltrrd 2309	. . . . . . 7 ⊢ ((𝐴 ∈ 𝒫 1o ∧ 𝑥 ∈ 𝐴) → ∅ ∈ 𝐴)
11	10	snssd 3823	. . . . . 6 ⊢ ((𝐴 ∈ 𝒫 1o ∧ 𝑥 ∈ 𝐴) → {∅} ⊆ 𝐴)
12	4, 11	eqssd 3245	. . . . 5 ⊢ ((𝐴 ∈ 𝒫 1o ∧ 𝑥 ∈ 𝐴) → 𝐴 = {∅})
13	12, 2	eqtr4di 2282	. . . 4 ⊢ ((𝐴 ∈ 𝒫 1o ∧ 𝑥 ∈ 𝐴) → 𝐴 = 1o)
14	13	ex 115	. . 3 ⊢ (𝐴 ∈ 𝒫 1o → (𝑥 ∈ 𝐴 → 𝐴 = 1o))
15	14	exlimdv 1867	. 2 ⊢ (𝐴 ∈ 𝒫 1o → (∃𝑥 𝑥 ∈ 𝐴 → 𝐴 = 1o))
16	15	imp 124	1 ⊢ ((𝐴 ∈ 𝒫 1o ∧ ∃𝑥 𝑥 ∈ 𝐴) → 𝐴 = 1o)

Syntax hints:   → wi 4   ∧ wa 104   = wceq 1398  ∃wex 1541   ∈ wcel 2202   ⊆ wss 3201  ∅c0 3496  𝒫 cpw 3656  {csn 3673  1_oc1o 6618

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-in1 619  ax-in2 620  ax-io 717  ax-5 1496  ax-7 1497  ax-gen 1498  ax-ie1 1542  ax-ie2 1543  ax-8 1553  ax-10 1554  ax-11 1555  ax-i12 1556  ax-bndl 1558  ax-4 1559  ax-17 1575  ax-i9 1579  ax-ial 1583  ax-i5r 1584  ax-ext 2213

This theorem depends on definitions:  df-bi 117  df-tru 1401  df-nf 1510  df-sb 1811  df-clab 2218  df-cleq 2224  df-clel 2227  df-nfc 2364  df-v 2805  df-dif 3203  df-un 3205  df-in 3207  df-ss 3214  df-nul 3497  df-pw 3658  df-sn 3679  df-suc 4474  df-1o 6625

This theorem is referenced by:  pw1if  7486