Metamath Proof Explorer


Theorem etaslts

Description: A restatement of noeta using set less-than. (Contributed by Scott Fenton, 10-Aug-2024)

Ref Expression
Assertion etaslts ( ( 𝐴 <<s 𝐵 ∧ 𝑂 ∈ On ∧ ( bday “ ( 𝐴 ∪ 𝐵 ) ) ⊆ 𝑂 ) → ∃ 𝑥 ∈ No ( 𝐴 <<s { 𝑥 } ∧ { 𝑥 } <<s 𝐵 ∧ ( bday ‘ 𝑥 ) ⊆ 𝑂 ) )

Proof

Step Hyp Ref Expression
1 sltsss1 ⊢ ( 𝐴 <<s 𝐵 → 𝐴 ⊆ No )
2 sltsex1 ⊢ ( 𝐴 <<s 𝐵 → 𝐴 ∈ V )
3 1 2 jca ⊢ ( 𝐴 <<s 𝐵 → ( 𝐴 ⊆ No ∧ 𝐴 ∈ V ) )
4 sltsss2 ⊢ ( 𝐴 <<s 𝐵 → 𝐵 ⊆ No )
5 sltsex2 ⊢ ( 𝐴 <<s 𝐵 → 𝐵 ∈ V )
6 4 5 jca ⊢ ( 𝐴 <<s 𝐵 → ( 𝐵 ⊆ No ∧ 𝐵 ∈ V ) )
7 sltssep ⊢ ( 𝐴 <<s 𝐵 → ∀ 𝑦 ∈ 𝐴 ∀ 𝑧 ∈ 𝐵 𝑦 <s 𝑧 )
8 3 6 7 3jca ⊢ ( 𝐴 <<s 𝐵 → ( ( 𝐴 ⊆ No ∧ 𝐴 ∈ V ) ∧ ( 𝐵 ⊆ No ∧ 𝐵 ∈ V ) ∧ ∀ 𝑦 ∈ 𝐴 ∀ 𝑧 ∈ 𝐵 𝑦 <s 𝑧 ) )
9 8 3ad2ant1 ⊢ ( ( 𝐴 <<s 𝐵 ∧ 𝑂 ∈ On ∧ ( bday “ ( 𝐴 ∪ 𝐵 ) ) ⊆ 𝑂 ) → ( ( 𝐴 ⊆ No ∧ 𝐴 ∈ V ) ∧ ( 𝐵 ⊆ No ∧ 𝐵 ∈ V ) ∧ ∀ 𝑦 ∈ 𝐴 ∀ 𝑧 ∈ 𝐵 𝑦 <s 𝑧 ) )
10 3simpc ⊢ ( ( 𝐴 <<s 𝐵 ∧ 𝑂 ∈ On ∧ ( bday “ ( 𝐴 ∪ 𝐵 ) ) ⊆ 𝑂 ) → ( 𝑂 ∈ On ∧ ( bday “ ( 𝐴 ∪ 𝐵 ) ) ⊆ 𝑂 ) )
11 noeta ⊢ ( ( ( ( 𝐴 ⊆ No ∧ 𝐴 ∈ V ) ∧ ( 𝐵 ⊆ No ∧ 𝐵 ∈ V ) ∧ ∀ 𝑦 ∈ 𝐴 ∀ 𝑧 ∈ 𝐵 𝑦 <s 𝑧 ) ∧ ( 𝑂 ∈ On ∧ ( bday “ ( 𝐴 ∪ 𝐵 ) ) ⊆ 𝑂 ) ) → ∃ 𝑥 ∈ No ( ∀ 𝑦 ∈ 𝐴 𝑦 <s 𝑥 ∧ ∀ 𝑧 ∈ 𝐵 𝑥 <s 𝑧 ∧ ( bday ‘ 𝑥 ) ⊆ 𝑂 ) )
12 9 10 11 syl2anc ⊢ ( ( 𝐴 <<s 𝐵 ∧ 𝑂 ∈ On ∧ ( bday “ ( 𝐴 ∪ 𝐵 ) ) ⊆ 𝑂 ) → ∃ 𝑥 ∈ No ( ∀ 𝑦 ∈ 𝐴 𝑦 <s 𝑥 ∧ ∀ 𝑧 ∈ 𝐵 𝑥 <s 𝑧 ∧ ( bday ‘ 𝑥 ) ⊆ 𝑂 ) )
13 2 ad2antrr ⊢ ( ( ( 𝐴 <<s 𝐵 ∧ 𝑂 ∈ On ) ∧ ( 𝑥 ∈ No ∧ ( ∀ 𝑦 ∈ 𝐴 𝑦 <s 𝑥 ∧ ∀ 𝑧 ∈ 𝐵 𝑥 <s 𝑧 ∧ ( bday ‘ 𝑥 ) ⊆ 𝑂 ) ) ) → 𝐴 ∈ V )
14 vsnex ⊢ { 𝑥 } ∈ V
15 13 14 jctir ⊢ ( ( ( 𝐴 <<s 𝐵 ∧ 𝑂 ∈ On ) ∧ ( 𝑥 ∈ No ∧ ( ∀ 𝑦 ∈ 𝐴 𝑦 <s 𝑥 ∧ ∀ 𝑧 ∈ 𝐵 𝑥 <s 𝑧 ∧ ( bday ‘ 𝑥 ) ⊆ 𝑂 ) ) ) → ( 𝐴 ∈ V ∧ { 𝑥 } ∈ V ) )
16 1 ad2antrr ⊢ ( ( ( 𝐴 <<s 𝐵 ∧ 𝑂 ∈ On ) ∧ ( 𝑥 ∈ No ∧ ( ∀ 𝑦 ∈ 𝐴 𝑦 <s 𝑥 ∧ ∀ 𝑧 ∈ 𝐵 𝑥 <s 𝑧 ∧ ( bday ‘ 𝑥 ) ⊆ 𝑂 ) ) ) → 𝐴 ⊆ No )
17 snssi ⊢ ( 𝑥 ∈ No → { 𝑥 } ⊆ No )
18 17 ad2antrl ⊢ ( ( ( 𝐴 <<s 𝐵 ∧ 𝑂 ∈ On ) ∧ ( 𝑥 ∈ No ∧ ( ∀ 𝑦 ∈ 𝐴 𝑦 <s 𝑥 ∧ ∀ 𝑧 ∈ 𝐵 𝑥 <s 𝑧 ∧ ( bday ‘ 𝑥 ) ⊆ 𝑂 ) ) ) → { 𝑥 } ⊆ No )
19 simprr1 ⊢ ( ( ( 𝐴 <<s 𝐵 ∧ 𝑂 ∈ On ) ∧ ( 𝑥 ∈ No ∧ ( ∀ 𝑦 ∈ 𝐴 𝑦 <s 𝑥 ∧ ∀ 𝑧 ∈ 𝐵 𝑥 <s 𝑧 ∧ ( bday ‘ 𝑥 ) ⊆ 𝑂 ) ) ) → ∀ 𝑦 ∈ 𝐴 𝑦 <s 𝑥 )
20 vex ⊢ 𝑥 ∈ V
21 breq2 ⊢ ( 𝑧 = 𝑥 → ( 𝑦 <s 𝑧 ↔ 𝑦 <s 𝑥 ) )
22 20 21 ralsn ⊢ ( ∀ 𝑧 ∈ { 𝑥 } 𝑦 <s 𝑧 ↔ 𝑦 <s 𝑥 )
23 22 ralbii ⊢ ( ∀ 𝑦 ∈ 𝐴 ∀ 𝑧 ∈ { 𝑥 } 𝑦 <s 𝑧 ↔ ∀ 𝑦 ∈ 𝐴 𝑦 <s 𝑥 )
24 19 23 sylibr ⊢ ( ( ( 𝐴 <<s 𝐵 ∧ 𝑂 ∈ On ) ∧ ( 𝑥 ∈ No ∧ ( ∀ 𝑦 ∈ 𝐴 𝑦 <s 𝑥 ∧ ∀ 𝑧 ∈ 𝐵 𝑥 <s 𝑧 ∧ ( bday ‘ 𝑥 ) ⊆ 𝑂 ) ) ) → ∀ 𝑦 ∈ 𝐴 ∀ 𝑧 ∈ { 𝑥 } 𝑦 <s 𝑧 )
25 16 18 24 3jca ⊢ ( ( ( 𝐴 <<s 𝐵 ∧ 𝑂 ∈ On ) ∧ ( 𝑥 ∈ No ∧ ( ∀ 𝑦 ∈ 𝐴 𝑦 <s 𝑥 ∧ ∀ 𝑧 ∈ 𝐵 𝑥 <s 𝑧 ∧ ( bday ‘ 𝑥 ) ⊆ 𝑂 ) ) ) → ( 𝐴 ⊆ No ∧ { 𝑥 } ⊆ No ∧ ∀ 𝑦 ∈ 𝐴 ∀ 𝑧 ∈ { 𝑥 } 𝑦 <s 𝑧 ) )
26 brslts ⊢ ( 𝐴 <<s { 𝑥 } ↔ ( ( 𝐴 ∈ V ∧ { 𝑥 } ∈ V ) ∧ ( 𝐴 ⊆ No ∧ { 𝑥 } ⊆ No ∧ ∀ 𝑦 ∈ 𝐴 ∀ 𝑧 ∈ { 𝑥 } 𝑦 <s 𝑧 ) ) )
27 15 25 26 sylanbrc ⊢ ( ( ( 𝐴 <<s 𝐵 ∧ 𝑂 ∈ On ) ∧ ( 𝑥 ∈ No ∧ ( ∀ 𝑦 ∈ 𝐴 𝑦 <s 𝑥 ∧ ∀ 𝑧 ∈ 𝐵 𝑥 <s 𝑧 ∧ ( bday ‘ 𝑥 ) ⊆ 𝑂 ) ) ) → 𝐴 <<s { 𝑥 } )
28 5 ad2antrr ⊢ ( ( ( 𝐴 <<s 𝐵 ∧ 𝑂 ∈ On ) ∧ ( 𝑥 ∈ No ∧ ( ∀ 𝑦 ∈ 𝐴 𝑦 <s 𝑥 ∧ ∀ 𝑧 ∈ 𝐵 𝑥 <s 𝑧 ∧ ( bday ‘ 𝑥 ) ⊆ 𝑂 ) ) ) → 𝐵 ∈ V )
29 28 14 jctil ⊢ ( ( ( 𝐴 <<s 𝐵 ∧ 𝑂 ∈ On ) ∧ ( 𝑥 ∈ No ∧ ( ∀ 𝑦 ∈ 𝐴 𝑦 <s 𝑥 ∧ ∀ 𝑧 ∈ 𝐵 𝑥 <s 𝑧 ∧ ( bday ‘ 𝑥 ) ⊆ 𝑂 ) ) ) → ( { 𝑥 } ∈ V ∧ 𝐵 ∈ V ) )
30 4 ad2antrr ⊢ ( ( ( 𝐴 <<s 𝐵 ∧ 𝑂 ∈ On ) ∧ ( 𝑥 ∈ No ∧ ( ∀ 𝑦 ∈ 𝐴 𝑦 <s 𝑥 ∧ ∀ 𝑧 ∈ 𝐵 𝑥 <s 𝑧 ∧ ( bday ‘ 𝑥 ) ⊆ 𝑂 ) ) ) → 𝐵 ⊆ No )
31 simprr2 ⊢ ( ( ( 𝐴 <<s 𝐵 ∧ 𝑂 ∈ On ) ∧ ( 𝑥 ∈ No ∧ ( ∀ 𝑦 ∈ 𝐴 𝑦 <s 𝑥 ∧ ∀ 𝑧 ∈ 𝐵 𝑥 <s 𝑧 ∧ ( bday ‘ 𝑥 ) ⊆ 𝑂 ) ) ) → ∀ 𝑧 ∈ 𝐵 𝑥 <s 𝑧 )
32 breq1 ⊢ ( 𝑦 = 𝑥 → ( 𝑦 <s 𝑧 ↔ 𝑥 <s 𝑧 ) )
33 32 ralbidv ⊢ ( 𝑦 = 𝑥 → ( ∀ 𝑧 ∈ 𝐵 𝑦 <s 𝑧 ↔ ∀ 𝑧 ∈ 𝐵 𝑥 <s 𝑧 ) )
34 20 33 ralsn ⊢ ( ∀ 𝑦 ∈ { 𝑥 } ∀ 𝑧 ∈ 𝐵 𝑦 <s 𝑧 ↔ ∀ 𝑧 ∈ 𝐵 𝑥 <s 𝑧 )
35 31 34 sylibr ⊢ ( ( ( 𝐴 <<s 𝐵 ∧ 𝑂 ∈ On ) ∧ ( 𝑥 ∈ No ∧ ( ∀ 𝑦 ∈ 𝐴 𝑦 <s 𝑥 ∧ ∀ 𝑧 ∈ 𝐵 𝑥 <s 𝑧 ∧ ( bday ‘ 𝑥 ) ⊆ 𝑂 ) ) ) → ∀ 𝑦 ∈ { 𝑥 } ∀ 𝑧 ∈ 𝐵 𝑦 <s 𝑧 )
36 18 30 35 3jca ⊢ ( ( ( 𝐴 <<s 𝐵 ∧ 𝑂 ∈ On ) ∧ ( 𝑥 ∈ No ∧ ( ∀ 𝑦 ∈ 𝐴 𝑦 <s 𝑥 ∧ ∀ 𝑧 ∈ 𝐵 𝑥 <s 𝑧 ∧ ( bday ‘ 𝑥 ) ⊆ 𝑂 ) ) ) → ( { 𝑥 } ⊆ No ∧ 𝐵 ⊆ No ∧ ∀ 𝑦 ∈ { 𝑥 } ∀ 𝑧 ∈ 𝐵 𝑦 <s 𝑧 ) )
37 brslts ⊢ ( { 𝑥 } <<s 𝐵 ↔ ( ( { 𝑥 } ∈ V ∧ 𝐵 ∈ V ) ∧ ( { 𝑥 } ⊆ No ∧ 𝐵 ⊆ No ∧ ∀ 𝑦 ∈ { 𝑥 } ∀ 𝑧 ∈ 𝐵 𝑦 <s 𝑧 ) ) )
38 29 36 37 sylanbrc ⊢ ( ( ( 𝐴 <<s 𝐵 ∧ 𝑂 ∈ On ) ∧ ( 𝑥 ∈ No ∧ ( ∀ 𝑦 ∈ 𝐴 𝑦 <s 𝑥 ∧ ∀ 𝑧 ∈ 𝐵 𝑥 <s 𝑧 ∧ ( bday ‘ 𝑥 ) ⊆ 𝑂 ) ) ) → { 𝑥 } <<s 𝐵 )
39 simprr3 ⊢ ( ( ( 𝐴 <<s 𝐵 ∧ 𝑂 ∈ On ) ∧ ( 𝑥 ∈ No ∧ ( ∀ 𝑦 ∈ 𝐴 𝑦 <s 𝑥 ∧ ∀ 𝑧 ∈ 𝐵 𝑥 <s 𝑧 ∧ ( bday ‘ 𝑥 ) ⊆ 𝑂 ) ) ) → ( bday ‘ 𝑥 ) ⊆ 𝑂 )
40 27 38 39 3jca ⊢ ( ( ( 𝐴 <<s 𝐵 ∧ 𝑂 ∈ On ) ∧ ( 𝑥 ∈ No ∧ ( ∀ 𝑦 ∈ 𝐴 𝑦 <s 𝑥 ∧ ∀ 𝑧 ∈ 𝐵 𝑥 <s 𝑧 ∧ ( bday ‘ 𝑥 ) ⊆ 𝑂 ) ) ) → ( 𝐴 <<s { 𝑥 } ∧ { 𝑥 } <<s 𝐵 ∧ ( bday ‘ 𝑥 ) ⊆ 𝑂 ) )
41 40 expr ⊢ ( ( ( 𝐴 <<s 𝐵 ∧ 𝑂 ∈ On ) ∧ 𝑥 ∈ No ) → ( ( ∀ 𝑦 ∈ 𝐴 𝑦 <s 𝑥 ∧ ∀ 𝑧 ∈ 𝐵 𝑥 <s 𝑧 ∧ ( bday ‘ 𝑥 ) ⊆ 𝑂 ) → ( 𝐴 <<s { 𝑥 } ∧ { 𝑥 } <<s 𝐵 ∧ ( bday ‘ 𝑥 ) ⊆ 𝑂 ) ) )
42 41 reximdva ⊢ ( ( 𝐴 <<s 𝐵 ∧ 𝑂 ∈ On ) → ( ∃ 𝑥 ∈ No ( ∀ 𝑦 ∈ 𝐴 𝑦 <s 𝑥 ∧ ∀ 𝑧 ∈ 𝐵 𝑥 <s 𝑧 ∧ ( bday ‘ 𝑥 ) ⊆ 𝑂 ) → ∃ 𝑥 ∈ No ( 𝐴 <<s { 𝑥 } ∧ { 𝑥 } <<s 𝐵 ∧ ( bday ‘ 𝑥 ) ⊆ 𝑂 ) ) )
43 42 3adant3 ⊢ ( ( 𝐴 <<s 𝐵 ∧ 𝑂 ∈ On ∧ ( bday “ ( 𝐴 ∪ 𝐵 ) ) ⊆ 𝑂 ) → ( ∃ 𝑥 ∈ No ( ∀ 𝑦 ∈ 𝐴 𝑦 <s 𝑥 ∧ ∀ 𝑧 ∈ 𝐵 𝑥 <s 𝑧 ∧ ( bday ‘ 𝑥 ) ⊆ 𝑂 ) → ∃ 𝑥 ∈ No ( 𝐴 <<s { 𝑥 } ∧ { 𝑥 } <<s 𝐵 ∧ ( bday ‘ 𝑥 ) ⊆ 𝑂 ) ) )
44 12 43 mpd ⊢ ( ( 𝐴 <<s 𝐵 ∧ 𝑂 ∈ On ∧ ( bday “ ( 𝐴 ∪ 𝐵 ) ) ⊆ 𝑂 ) → ∃ 𝑥 ∈ No ( 𝐴 <<s { 𝑥 } ∧ { 𝑥 } <<s 𝐵 ∧ ( bday ‘ 𝑥 ) ⊆ 𝑂 ) )