Theorem cuteq1 27828

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 27825	. . . . . 6 ⊢ ( bday ‘ 1s ) = 1o
4		df-1o 8407	. . . . . 6 ⊢ 1o = suc ∅
5	3, 4	eqtri 2760	. . . . 5 ⊢ ( bday ‘ 1s ) = suc ∅
6		sltssep 27778	. . . . . . . . . . . . . 14 ⊢ (𝐴 <<s { 0s } → ∀𝑥 ∈ 𝐴 ∀𝑦 ∈ { 0s }𝑥 <s 𝑦)
7		dfral2 3089	. . . . . . . . . . . . . . . 16 ⊢ (∀𝑦 ∈ { 0s }𝑥 <s 𝑦 ↔ ¬ ∃𝑦 ∈ { 0s } ¬ 𝑥 <s 𝑦)
8	7	ralbii 3084	. . . . . . . . . . . . . . 15 ⊢ (∀𝑥 ∈ 𝐴 ∀𝑦 ∈ { 0s }𝑥 <s 𝑦 ↔ ∀𝑥 ∈ 𝐴 ¬ ∃𝑦 ∈ { 0s } ¬ 𝑥 <s 𝑦)
9		ralnex 3064	. . . . . . . . . . . . . . 15 ⊢ (∀𝑥 ∈ 𝐴 ¬ ∃𝑦 ∈ { 0s } ¬ 𝑥 <s 𝑦 ↔ ¬ ∃𝑥 ∈ 𝐴 ∃𝑦 ∈ { 0s } ¬ 𝑥 <s 𝑦)
10	8, 9	bitri 275	. . . . . . . . . . . . . 14 ⊢ (∀𝑥 ∈ 𝐴 ∀𝑦 ∈ { 0s }𝑥 <s 𝑦 ↔ ¬ ∃𝑥 ∈ 𝐴 ∃𝑦 ∈ { 0s } ¬ 𝑥 <s 𝑦)
11	6, 10	sylib 218	. . . . . . . . . . . . 13 ⊢ (𝐴 <<s { 0s } → ¬ ∃𝑥 ∈ 𝐴 ∃𝑦 ∈ { 0s } ¬ 𝑥 <s 𝑦)
12		cuteq1.1	. . . . . . . . . . . . . . 15 ⊢ (𝜑 → 0s ∈ 𝐴)
13		0no 27820	. . . . . . . . . . . . . . . 16 ⊢ 0s ∈ No
14		ltsirr 27729	. . . . . . . . . . . . . . . 16 ⊢ ( 0s ∈ No → ¬ 0s <s 0s )
15	13, 14	ax-mp 5	. . . . . . . . . . . . . . 15 ⊢ ¬ 0s <s 0s
16		breq1 5103	. . . . . . . . . . . . . . . . 17 ⊢ (𝑥 = 0s → (𝑥 <s 0s ↔ 0s <s 0s ))
17	16	notbid 318	. . . . . . . . . . . . . . . 16 ⊢ (𝑥 = 0s → (¬ 𝑥 <s 0s ↔ ¬ 0s <s 0s ))
18	17	rspcev 3578	. . . . . . . . . . . . . . 15 ⊢ (( 0s ∈ 𝐴 ∧ ¬ 0s <s 0s ) → ∃𝑥 ∈ 𝐴 ¬ 𝑥 <s 0s )
19	12, 15, 18	sylancl 587	. . . . . . . . . . . . . 14 ⊢ (𝜑 → ∃𝑥 ∈ 𝐴 ¬ 𝑥 <s 0s )
20	13	elexi 3465	. . . . . . . . . . . . . . . 16 ⊢ 0s ∈ V
21		breq2 5104	. . . . . . . . . . . . . . . . 17 ⊢ (𝑦 = 0s → (𝑥 <s 𝑦 ↔ 𝑥 <s 0s ))
22	21	notbid 318	. . . . . . . . . . . . . . . 16 ⊢ (𝑦 = 0s → (¬ 𝑥 <s 𝑦 ↔ ¬ 𝑥 <s 0s ))
23	20, 22	rexsn 4641	. . . . . . . . . . . . . . 15 ⊢ (∃𝑦 ∈ { 0s } ¬ 𝑥 <s 𝑦 ↔ ¬ 𝑥 <s 0s )
24	23	rexbii 3085	. . . . . . . . . . . . . 14 ⊢ (∃𝑥 ∈ 𝐴 ∃𝑦 ∈ { 0s } ¬ 𝑥 <s 𝑦 ↔ ∃𝑥 ∈ 𝐴 ¬ 𝑥 <s 0s )
25	19, 24	sylibr 234	. . . . . . . . . . . . 13 ⊢ (𝜑 → ∃𝑥 ∈ 𝐴 ∃𝑦 ∈ { 0s } ¬ 𝑥 <s 𝑦)
26	11, 25	nsyl3 138	. . . . . . . . . . . 12 ⊢ (𝜑 → ¬ 𝐴 <<s { 0s })
27	26	adantr 480	. . . . . . . . . . 11 ⊢ ((𝜑 ∧ 𝑥 ∈ No ) → ¬ 𝐴 <<s { 0s })
28		sneq 4592	. . . . . . . . . . . . 13 ⊢ (𝑥 = 0s → {𝑥} = { 0s })
29	28	breq2d 5112	. . . . . . . . . . . 12 ⊢ (𝑥 = 0s → (𝐴 <<s {𝑥} ↔ 𝐴 <<s { 0s }))
30	29	notbid 318	. . . . . . . . . . 11 ⊢ (𝑥 = 0s → (¬ 𝐴 <<s {𝑥} ↔ ¬ 𝐴 <<s { 0s }))
31	27, 30	syl5ibrcom 247	. . . . . . . . . 10 ⊢ ((𝜑 ∧ 𝑥 ∈ No ) → (𝑥 = 0s → ¬ 𝐴 <<s {𝑥}))
32	31	necon2ad 2948	. . . . . . . . 9 ⊢ ((𝜑 ∧ 𝑥 ∈ No ) → (𝐴 <<s {𝑥} → 𝑥 ≠ 0s ))
33	32	adantrd 491	. . . . . . . 8 ⊢ ((𝜑 ∧ 𝑥 ∈ No ) → ((𝐴 <<s {𝑥} ∧ {𝑥} <<s 𝐵) → 𝑥 ≠ 0s ))
34	33	impr 454	. . . . . . 7 ⊢ ((𝜑 ∧ (𝑥 ∈ No ∧ (𝐴 <<s {𝑥} ∧ {𝑥} <<s 𝐵))) → 𝑥 ≠ 0s )
35		bday0b 27824	. . . . . . . . 9 ⊢ (𝑥 ∈ No → (( bday ‘𝑥) = ∅ ↔ 𝑥 = 0s ))
36	35	ad2antrl 729	. . . . . . . 8 ⊢ ((𝜑 ∧ (𝑥 ∈ No ∧ (𝐴 <<s {𝑥} ∧ {𝑥} <<s 𝐵))) → (( bday ‘𝑥) = ∅ ↔ 𝑥 = 0s ))
37	36	necon3bid 2977	. . . . . . 7 ⊢ ((𝜑 ∧ (𝑥 ∈ No ∧ (𝐴 <<s {𝑥} ∧ {𝑥} <<s 𝐵))) → (( bday ‘𝑥) ≠ ∅ ↔ 𝑥 ≠ 0s ))
38	34, 37	mpbird 257	. . . . . 6 ⊢ ((𝜑 ∧ (𝑥 ∈ No ∧ (𝐴 <<s {𝑥} ∧ {𝑥} <<s 𝐵))) → ( bday ‘𝑥) ≠ ∅)
39		bdayon 27763	. . . . . . . . 9 ⊢ ( bday ‘𝑥) ∈ On
40	39	onordi 6438	. . . . . . . 8 ⊢ Ord ( bday ‘𝑥)
41		ord0eln0 6381	. . . . . . . 8 ⊢ (Ord ( bday ‘𝑥) → (∅ ∈ ( bday ‘𝑥) ↔ ( bday ‘𝑥) ≠ ∅))
42	40, 41	ax-mp 5	. . . . . . 7 ⊢ (∅ ∈ ( bday ‘𝑥) ↔ ( bday ‘𝑥) ≠ ∅)
43		0elon 6380	. . . . . . . 8 ⊢ ∅ ∈ On
44	43, 39	onsucssi 7793	. . . . . . 7 ⊢ (∅ ∈ ( bday ‘𝑥) ↔ suc ∅ ⊆ ( bday ‘𝑥))
45	42, 44	bitr3i 277	. . . . . 6 ⊢ (( bday ‘𝑥) ≠ ∅ ↔ suc ∅ ⊆ ( bday ‘𝑥))
46	38, 45	sylib 218	. . . . 5 ⊢ ((𝜑 ∧ (𝑥 ∈ No ∧ (𝐴 <<s {𝑥} ∧ {𝑥} <<s 𝐵))) → suc ∅ ⊆ ( bday ‘𝑥))
47	5, 46	eqsstrid 3974	. . . 4 ⊢ ((𝜑 ∧ (𝑥 ∈ No ∧ (𝐴 <<s {𝑥} ∧ {𝑥} <<s 𝐵))) → ( bday ‘ 1s ) ⊆ ( bday ‘𝑥))
48	47	expr 456	. . 3 ⊢ ((𝜑 ∧ 𝑥 ∈ No ) → ((𝐴 <<s {𝑥} ∧ {𝑥} <<s 𝐵) → ( bday ‘ 1s ) ⊆ ( bday ‘𝑥)))
49	48	ralrimiva 3130	. 2 ⊢ (𝜑 → ∀𝑥 ∈ No ((𝐴 <<s {𝑥} ∧ {𝑥} <<s 𝐵) → ( bday ‘ 1s ) ⊆ ( bday ‘𝑥)))
50		1no 27821	. . . . . . 7 ⊢ 1s ∈ No
51	50	elexi 3465	. . . . . 6 ⊢ 1s ∈ V
52	51	snnz 4735	. . . . 5 ⊢ { 1s } ≠ ∅
53		sltstr 27798	. . . . 5 ⊢ ((𝐴 <<s { 1s } ∧ { 1s } <<s 𝐵 ∧ { 1s } ≠ ∅) → 𝐴 <<s 𝐵)
54	52, 53	mp3an3 1453	. . . 4 ⊢ ((𝐴 <<s { 1s } ∧ { 1s } <<s 𝐵) → 𝐴 <<s 𝐵)
55	1, 2, 54	syl2anc 585	. . 3 ⊢ (𝜑 → 𝐴 <<s 𝐵)
56		eqcuts2 27797	. . 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 587	. 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 1344	1 ⊢ (𝜑 → (𝐴 |s 𝐵) = 1s )

Syntax hints:  ¬ wn 3   → wi 4   ↔ wb 206   ∧ wa 395   ∧ w3a 1087   = wceq 1542   ∈ wcel 2114   ≠ wne 2933  ∀wral 3052  ∃wrex 3062   ⊆ wss 3903  ∅c0 4287  {csn 4582   class class class wbr 5100  Ord word 6324  suc csuc 6327  ‘cfv 6500  (class class class)co 7368  1_oc1o 8400   No csur 27622   <s clts 27623   bday cbday 27624   <<s cslts 27768   |s ccuts 27770   0_s c0s 27816   1_s c1s 27817

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1797  ax-4 1811  ax-5 1912  ax-6 1969  ax-7 2010  ax-8 2116  ax-9 2124  ax-10 2147  ax-11 2163  ax-12 2185  ax-ext 2709  ax-rep 5226  ax-sep 5243  ax-nul 5253  ax-pow 5312  ax-pr 5379  ax-un 7690

This theorem depends on definitions:  df-bi 207  df-an 396  df-or 849  df-3or 1088  df-3an 1089  df-tru 1545  df-fal 1555  df-ex 1782  df-nf 1786  df-sb 2069  df-mo 2540  df-eu 2570  df-clab 2716  df-cleq 2729  df-clel 2812  df-nfc 2886  df-ne 2934  df-ral 3053  df-rex 3063  df-rmo 3352  df-reu 3353  df-rab 3402  df-v 3444  df-sbc 3743  df-csb 3852  df-dif 3906  df-un 3908  df-in 3910  df-ss 3920  df-pss 3923  df-nul 4288  df-if 4482  df-pw 4558  df-sn 4583  df-pr 4585  df-tp 4587  df-op 4589  df-uni 4866  df-int 4905  df-br 5101  df-opab 5163  df-mpt 5182  df-tr 5208  df-id 5527  df-eprel 5532  df-po 5540  df-so 5541  df-fr 5585  df-we 5587  df-xp 5638  df-rel 5639  df-cnv 5640  df-co 5641  df-dm 5642  df-rn 5643  df-res 5644  df-ima 5645  df-ord 6328  df-on 6329  df-suc 6331  df-iota 6456  df-fun 6502  df-fn 6503  df-f 6504  df-f1 6505  df-fo 6506  df-f1o 6507  df-fv 6508  df-riota 7325  df-ov 7371  df-oprab 7372  df-mpo 7373  df-1o 8407  df-2o 8408  df-no 27625  df-lts 27626  df-bday 27627  df-slts 27769  df-cuts 27771  df-0s 27818  df-1s 27819

This theorem is referenced by:  precsexlem11  28228