Theorem cuteq1 28215

Description: Condition for a surreal cut to equal one. (Contributed by Scott Fenton, 12-Mar-2025.)

Hypotheses

Ref	Expression
cuteq1.1	⊢ (𝜑 → 0s ∈ 𝐴)
cuteq1.2	⊢ (𝜑 → 𝐴 <<s { 1s })
cuteq1.3	⊢ (𝜑 → { 1s } <<s 𝐵)

Assertion

Ref	Expression
cuteq1	⊢ (𝜑 → (𝐴 |s 𝐵) = 1s )

Proof of Theorem cuteq1

Dummy variables 𝑥 𝑦 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		cuteq1.2	. 2 ⊢ (𝜑 → 𝐴 <<s { 1s })
2		cuteq1.3	. 2 ⊢ (𝜑 → { 1s } <<s 𝐵)
3		bday1 28212	. . . . . 6 ⊢ (bday‘ 1s ) = 1o
4		df-1o 8487	. . . . . 6 ⊢ 1o = suc ∅
5	3, 4	eqtri 2786	. . . . 5 ⊢ (bday‘ 1s ) = suc ∅
6		sltssep 28165	. . . . . . . . . . . . . 14 ⊢ (𝐴 <<s { 0s } → ∀𝑥 ∈ 𝐴 ∀𝑦 ∈ { 0s }𝑥 <s 𝑦)
7		dfral2 3116	. . . . . . . . . . . . . . . 16 ⊢ (∀𝑦 ∈ { 0s }𝑥 <s 𝑦 ↔ ¬ ∃𝑦 ∈ { 0s } ¬ 𝑥 <s 𝑦)
8	7	ralbii 3111	. . . . . . . . . . . . . . 15 ⊢ (∀𝑥 ∈ 𝐴 ∀𝑦 ∈ { 0s }𝑥 <s 𝑦 ↔ ∀𝑥 ∈ 𝐴 ¬ ∃𝑦 ∈ { 0s } ¬ 𝑥 <s 𝑦)
9		ralnex 3091	. . . . . . . . . . . . . . 15 ⊢ (∀𝑥 ∈ 𝐴 ¬ ∃𝑦 ∈ { 0s } ¬ 𝑥 <s 𝑦 ↔ ¬ ∃𝑥 ∈ 𝐴 ∃𝑦 ∈ { 0s } ¬ 𝑥 <s 𝑦)
10	8, 9	bitri 278	. . . . . . . . . . . . . 14 ⊢ (∀𝑥 ∈ 𝐴 ∀𝑦 ∈ { 0s }𝑥 <s 𝑦 ↔ ¬ ∃𝑥 ∈ 𝐴 ∃𝑦 ∈ { 0s } ¬ 𝑥 <s 𝑦)
11	6, 10	sylib 221	. . . . . . . . . . . . 13 ⊢ (𝐴 <<s { 0s } → ¬ ∃𝑥 ∈ 𝐴 ∃𝑦 ∈ { 0s } ¬ 𝑥 <s 𝑦)
12		cuteq1.1	. . . . . . . . . . . . . . 15 ⊢ (𝜑 → 0s ∈ 𝐴)
13		0no 28207	. . . . . . . . . . . . . . . 16 ⊢ 0s ∈ No
14		ltsirr 28115	. . . . . . . . . . . . . . . 16 ⊢ ( 0s ∈ No → ¬ 0s <s 0s )
15	13, 14	ax-mp 5	. . . . . . . . . . . . . . 15 ⊢ ¬ 0s <s 0s
16		breq1 5108	. . . . . . . . . . . . . . . . 17 ⊢ (𝑥 = 0s → (𝑥 <s 0s ↔ 0s <s 0s ))
17	16	notbid 321	. . . . . . . . . . . . . . . 16 ⊢ (𝑥 = 0s → (¬ 𝑥 <s 0s ↔ ¬ 0s <s 0s ))
18	17	rspcev 3579	. . . . . . . . . . . . . . 15 ⊢ (( 0s ∈ 𝐴 ∧ ¬ 0s <s 0s ) → ∃𝑥 ∈ 𝐴 ¬ 𝑥 <s 0s )
19	12, 15, 18	sylancl 598	. . . . . . . . . . . . . 14 ⊢ (𝜑 → ∃𝑥 ∈ 𝐴 ¬ 𝑥 <s 0s )
20	13	elexi 3475	. . . . . . . . . . . . . . . 16 ⊢ 0s ∈ V
21		breq2 5109	. . . . . . . . . . . . . . . . 17 ⊢ (𝑦 = 0s → (𝑥 <s 𝑦 ↔ 𝑥 <s 0s ))
22	21	notbid 321	. . . . . . . . . . . . . . . 16 ⊢ (𝑦 = 0s → (¬ 𝑥 <s 𝑦 ↔ ¬ 𝑥 <s 0s ))
23	20, 22	rexsn 4642	. . . . . . . . . . . . . . 15 ⊢ (∃𝑦 ∈ { 0s } ¬ 𝑥 <s 𝑦 ↔ ¬ 𝑥 <s 0s )
24	23	rexbii 3112	. . . . . . . . . . . . . 14 ⊢ (∃𝑥 ∈ 𝐴 ∃𝑦 ∈ { 0s } ¬ 𝑥 <s 𝑦 ↔ ∃𝑥 ∈ 𝐴 ¬ 𝑥 <s 0s )
25	19, 24	sylibr 237	. . . . . . . . . . . . 13 ⊢ (𝜑 → ∃𝑥 ∈ 𝐴 ∃𝑦 ∈ { 0s } ¬ 𝑥 <s 𝑦)
26	11, 25	nsyl3 139	. . . . . . . . . . . 12 ⊢ (𝜑 → ¬ 𝐴 <<s { 0s })
27	26	adantr 486	. . . . . . . . . . 11 ⊢ ((𝜑 ∧ 𝑥 ∈ No) → ¬ 𝐴 <<s { 0s })
28		sneq 4593	. . . . . . . . . . . . 13 ⊢ (𝑥 = 0s → {𝑥} = { 0s })
29	28	breq2d 5117	. . . . . . . . . . . 12 ⊢ (𝑥 = 0s → (𝐴 <<s {𝑥} ↔ 𝐴 <<s { 0s }))
30	29	notbid 321	. . . . . . . . . . 11 ⊢ (𝑥 = 0s → (¬ 𝐴 <<s {𝑥} ↔ ¬ 𝐴 <<s { 0s }))
31	27, 30	syl5ibrcom 250	. . . . . . . . . 10 ⊢ ((𝜑 ∧ 𝑥 ∈ No) → (𝑥 = 0s → ¬ 𝐴 <<s {𝑥}))
32	31	necon2ad 2973	. . . . . . . . 9 ⊢ ((𝜑 ∧ 𝑥 ∈ No) → (𝐴 <<s {𝑥} → 𝑥 ≠ 0s ))
33	32	adantrd 497	. . . . . . . 8 ⊢ ((𝜑 ∧ 𝑥 ∈ No) → ((𝐴 <<s {𝑥} ∧ {𝑥} <<s 𝐵) → 𝑥 ≠ 0s ))
34	33	impr 460	. . . . . . 7 ⊢ ((𝜑 ∧ (𝑥 ∈ No ∧ (𝐴 <<s {𝑥} ∧ {𝑥} <<s 𝐵))) → 𝑥 ≠ 0s )
35		bday0b 28211	. . . . . . . . 9 ⊢ (𝑥 ∈ No → ((bday‘𝑥) = ∅ ↔ 𝑥 = 0s ))
36	35	ad2antrl 741	. . . . . . . 8 ⊢ ((𝜑 ∧ (𝑥 ∈ No ∧ (𝐴 <<s {𝑥} ∧ {𝑥} <<s 𝐵))) → ((bday‘𝑥) = ∅ ↔ 𝑥 = 0s ))
37	36	necon3bid 3002	. . . . . . 7 ⊢ ((𝜑 ∧ (𝑥 ∈ No ∧ (𝐴 <<s {𝑥} ∧ {𝑥} <<s 𝐵))) → ((bday‘𝑥) ≠ ∅ ↔ 𝑥 ≠ 0s ))
38	34, 37	mpbird 260	. . . . . 6 ⊢ ((𝜑 ∧ (𝑥 ∈ No ∧ (𝐴 <<s {𝑥} ∧ {𝑥} <<s 𝐵))) → (bday‘𝑥) ≠ ∅)
39		bdayon 28150	. . . . . . . . 9 ⊢ (bday‘𝑥) ∈ On
40	39	onordi 6482	. . . . . . . 8 ⊢ Ord (bday‘𝑥)
41		ord0eln0 6425	. . . . . . . 8 ⊢ (Ord (bday‘𝑥) → (∅ ∈ (bday‘𝑥) ↔ (bday‘𝑥) ≠ ∅))
42	40, 41	ax-mp 5	. . . . . . 7 ⊢ (∅ ∈ (bday‘𝑥) ↔ (bday‘𝑥) ≠ ∅)
43		0elon 6424	. . . . . . . 8 ⊢ ∅ ∈ On
44	43, 39	onsucssi 7859	. . . . . . 7 ⊢ (∅ ∈ (bday‘𝑥) ↔ suc ∅ ⊆ (bday‘𝑥))
45	42, 44	bitr3i 280	. . . . . 6 ⊢ ((bday‘𝑥) ≠ ∅ ↔ suc ∅ ⊆ (bday‘𝑥))
46	38, 45	sylib 221	. . . . 5 ⊢ ((𝜑 ∧ (𝑥 ∈ No ∧ (𝐴 <<s {𝑥} ∧ {𝑥} <<s 𝐵))) → suc ∅ ⊆ (bday‘𝑥))
47	5, 46	eqsstrid 3950	. . . 4 ⊢ ((𝜑 ∧ (𝑥 ∈ No ∧ (𝐴 <<s {𝑥} ∧ {𝑥} <<s 𝐵))) → (bday‘ 1s ) ⊆ (bday‘𝑥))
48	47	expr 462	. . 3 ⊢ ((𝜑 ∧ 𝑥 ∈ No) → ((𝐴 <<s {𝑥} ∧ {𝑥} <<s 𝐵) → (bday‘ 1s ) ⊆ (bday‘𝑥)))
49	48	ralrimiva 3157	. 2 ⊢ (𝜑 → ∀𝑥 ∈ No ((𝐴 <<s {𝑥} ∧ {𝑥} <<s 𝐵) → (bday‘ 1s ) ⊆ (bday‘𝑥)))
50		1no 28208	. . . . . . 7 ⊢ 1s ∈ No
51	50	elexi 3475	. . . . . 6 ⊢ 1s ∈ V
52	51	snnz 4736	. . . . 5 ⊢ { 1s } ≠ ∅
53		sltstr 28185	. . . . 5 ⊢ ((𝐴 <<s { 1s } ∧ { 1s } <<s 𝐵 ∧ { 1s } ≠ ∅) → 𝐴 <<s 𝐵)
54	52, 53	mp3an3 1479	. . . 4 ⊢ ((𝐴 <<s { 1s } ∧ { 1s } <<s 𝐵) → 𝐴 <<s 𝐵)
55	1, 2, 54	syl2anc 596	. . 3 ⊢ (𝜑 → 𝐴 <<s 𝐵)
56		eqcuts2 28184	. . 3 ⊢ ((𝐴 <<s 𝐵 ∧ 1s ∈ No) → ((𝐴 |s 𝐵) = 1s ↔ (𝐴 <<s { 1s } ∧ { 1s } <<s 𝐵 ∧ ∀𝑥 ∈ No ((𝐴 <<s {𝑥} ∧ {𝑥} <<s 𝐵) → (bday‘ 1s ) ⊆ (bday‘𝑥)))))
57	55, 50, 56	sylancl 598	. 2 ⊢ (𝜑 → ((𝐴 |s 𝐵) = 1s ↔ (𝐴 <<s { 1s } ∧ { 1s } <<s 𝐵 ∧ ∀𝑥 ∈ No ((𝐴 <<s {𝑥} ∧ {𝑥} <<s 𝐵) → (bday‘ 1s ) ⊆ (bday‘𝑥)))))
58	1, 2, 49, 57	mpbir3and 1361	1 ⊢ (𝜑 → (𝐴 |s 𝐵) = 1s )

This proof depends on syntax axioms:  ¬ wn 3   → wi 4   ↔ wb 209   ∧ wa 401   ∧ w3a 1103   = wceq 1569   ∈ wcel 2146   ≠ wne 2958  ∀wral 3079  ∃wrex 3089   ⊆ wss 3899  ∅c0 4280  {csn 4587   class class class wbr 5105  Ord word 6367  suc csuc 6370  ‘cfv 6546  (class class class)co 7427  1_oc1o 8480  Nocsur 28009   <s clts 28010  bdaycbday 28011   <<s cslts 28155   |s ccuts 28157   0_s c0s 28203   1_s c1s 28204

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1827  ax-4 1841  ax-5 1944  ax-6 2001  ax-7 2042  ax-8 2148  ax-9 2156  ax-10 2179  ax-11 2196  ax-12 2215  ax-ext 2735  ax-rep 5234  ax-sep 5251  ax-nul 5262  ax-pow 5330  ax-pr 5394  ax-un 7758

This proof depends on definitions:  df-bi 210  df-an 402  df-or 862  df-3or 1104  df-3an 1105  df-tru 1572  df-fal 1582  df-ex 1812  df-nf 1816  df-sb 2101  df-mo 2567  df-eu 2597  df-clab 2742  df-cleq 2755  df-clel 2838  df-nfc 2912  df-ne 2959  df-ral 3080  df-rex 3090  df-rmo 3368  df-reu 3369  df-rab 3416  df-v 3455  df-sbc 3742  df-csb 3851  df-ss 3900  df-pss 4016  df-dif 4049  df-in 4093  df-un 4153  df-nul 4281  df-if 4485  df-pw 4561  df-sn 4588  df-pr 4590  df-tp 4592  df-op 4838  df-uni 4870  df-int 4910  df-br 5106  df-opab 5170  df-mpt 5189  df-tr 5215  df-id 5549  df-eprel 5554  df-po 5562  df-so 5563  df-fr 5607  df-we 5609  df-xp 5660  df-rel 5661  df-cnv 5662  df-co 5663  df-dm 5664  df-rn 5665  df-res 5666  df-ima 5667  df-ord 6371  df-on 6372  df-suc 6374  df-iota 6500  df-fun 6548  df-fn 6549  df-f 6550  df-f1 6551  df-fo 6552  df-f1o 6553  df-fv 6554  df-riota 7384  df-ov 7430  df-oprab 7431  df-mpo 7432  df-1o 8487  df-2o 8488  df-no 28012  df-lts 28013  df-bday 28014  df-slts 28156  df-cuts 28158  df-0s 28205  df-1s 28206

This theorem is used by:  precsexlem11  28615