Metamath Proof Explorer


Theorem harval3

Description: ( harA ) is the least cardinal that is greater than A . (Contributed by RP, 4-Nov-2023)

Ref Expression
Assertion harval3 ( 𝐴 ∈ dom card → ( har ‘ 𝐴 ) = ∩ { 𝑥 ∈ ran card ∣ 𝐴 ≺ 𝑥 } )

Proof

Step Hyp Ref Expression
1 harval2 ⊢ ( 𝐴 ∈ dom card → ( har ‘ 𝐴 ) = ∩ { 𝑦 ∈ On ∣ 𝐴 ≺ 𝑦 } )
2 vex ⊢ 𝑥 ∈ V
3 2 a1i ⊢ ( 𝐴 ∈ dom card → 𝑥 ∈ V )
4 elrncard ⊢ ( 𝑥 ∈ ran card ↔ ( 𝑥 ∈ On ∧ ∀ 𝑦 ∈ 𝑥 ¬ 𝑦 ≈ 𝑥 ) )
5 4 simplbi ⊢ ( 𝑥 ∈ ran card → 𝑥 ∈ On )
6 5 anim1i ⊢ ( ( 𝑥 ∈ ran card ∧ 𝐴 ≺ 𝑥 ) → ( 𝑥 ∈ On ∧ 𝐴 ≺ 𝑥 ) )
7 eleq1 ⊢ ( 𝑦 = 𝑥 → ( 𝑦 ∈ On ↔ 𝑥 ∈ On ) )
8 breq2 ⊢ ( 𝑦 = 𝑥 → ( 𝐴 ≺ 𝑦 ↔ 𝐴 ≺ 𝑥 ) )
9 7 8 anbi12d ⊢ ( 𝑦 = 𝑥 → ( ( 𝑦 ∈ On ∧ 𝐴 ≺ 𝑦 ) ↔ ( 𝑥 ∈ On ∧ 𝐴 ≺ 𝑥 ) ) )
10 6 9 imbitrrid ⊢ ( 𝑦 = 𝑥 → ( ( 𝑥 ∈ ran card ∧ 𝐴 ≺ 𝑥 ) → ( 𝑦 ∈ On ∧ 𝐴 ≺ 𝑦 ) ) )
11 10 adantl ⊢ ( ( 𝐴 ∈ dom card ∧ 𝑦 = 𝑥 ) → ( ( 𝑥 ∈ ran card ∧ 𝐴 ≺ 𝑥 ) → ( 𝑦 ∈ On ∧ 𝐴 ≺ 𝑦 ) ) )
12 ssidd ⊢ ( 𝐴 ∈ dom card → 𝑥 ⊆ 𝑥 )
13 3 11 12 intabssd ⊢ ( 𝐴 ∈ dom card → ∩ { 𝑦 ∣ ( 𝑦 ∈ On ∧ 𝐴 ≺ 𝑦 ) } ⊆ ∩ { 𝑥 ∣ ( 𝑥 ∈ ran card ∧ 𝐴 ≺ 𝑥 ) } )
14 vex ⊢ 𝑦 ∈ V
15 14 inex1 ⊢ ( 𝑦 ∩ ( card ‘ 𝑦 ) ) ∈ V
16 15 a1i ⊢ ( 𝐴 ∈ dom card → ( 𝑦 ∩ ( card ‘ 𝑦 ) ) ∈ V )
17 oncardid ⊢ ( 𝑦 ∈ On → ( card ‘ 𝑦 ) ≈ 𝑦 )
18 17 ensymd ⊢ ( 𝑦 ∈ On → 𝑦 ≈ ( card ‘ 𝑦 ) )
19 sdomentr ⊢ ( ( 𝐴 ≺ 𝑦 ∧ 𝑦 ≈ ( card ‘ 𝑦 ) ) → 𝐴 ≺ ( card ‘ 𝑦 ) )
20 19 a1i ⊢ ( 𝑦 ∈ On → ( ( 𝐴 ≺ 𝑦 ∧ 𝑦 ≈ ( card ‘ 𝑦 ) ) → 𝐴 ≺ ( card ‘ 𝑦 ) ) )
21 18 20 mpan2d ⊢ ( 𝑦 ∈ On → ( 𝐴 ≺ 𝑦 → 𝐴 ≺ ( card ‘ 𝑦 ) ) )
22 df-card ⊢ card = ( 𝑥 ∈ V ↦ ∩ { 𝑦 ∈ On ∣ 𝑦 ≈ 𝑥 } )
23 22 funmpt2 ⊢ Fun card
24 onenon ⊢ ( 𝑦 ∈ On → 𝑦 ∈ dom card )
25 fvelrn ⊢ ( ( Fun card ∧ 𝑦 ∈ dom card ) → ( card ‘ 𝑦 ) ∈ ran card )
26 23 24 25 sylancr ⊢ ( 𝑦 ∈ On → ( card ‘ 𝑦 ) ∈ ran card )
27 21 26 jctild ⊢ ( 𝑦 ∈ On → ( 𝐴 ≺ 𝑦 → ( ( card ‘ 𝑦 ) ∈ ran card ∧ 𝐴 ≺ ( card ‘ 𝑦 ) ) ) )
28 27 adantl ⊢ ( ( 𝑥 = ( 𝑦 ∩ ( card ‘ 𝑦 ) ) ∧ 𝑦 ∈ On ) → ( 𝐴 ≺ 𝑦 → ( ( card ‘ 𝑦 ) ∈ ran card ∧ 𝐴 ≺ ( card ‘ 𝑦 ) ) ) )
29 simpl ⊢ ( ( 𝑥 = ( 𝑦 ∩ ( card ‘ 𝑦 ) ) ∧ 𝑦 ∈ On ) → 𝑥 = ( 𝑦 ∩ ( card ‘ 𝑦 ) ) )
30 cardonle ⊢ ( 𝑦 ∈ On → ( card ‘ 𝑦 ) ⊆ 𝑦 )
31 30 adantl ⊢ ( ( 𝑥 = ( 𝑦 ∩ ( card ‘ 𝑦 ) ) ∧ 𝑦 ∈ On ) → ( card ‘ 𝑦 ) ⊆ 𝑦 )
32 sseqin2 ⊢ ( ( card ‘ 𝑦 ) ⊆ 𝑦 ↔ ( 𝑦 ∩ ( card ‘ 𝑦 ) ) = ( card ‘ 𝑦 ) )
33 31 32 sylib ⊢ ( ( 𝑥 = ( 𝑦 ∩ ( card ‘ 𝑦 ) ) ∧ 𝑦 ∈ On ) → ( 𝑦 ∩ ( card ‘ 𝑦 ) ) = ( card ‘ 𝑦 ) )
34 29 33 eqtrd ⊢ ( ( 𝑥 = ( 𝑦 ∩ ( card ‘ 𝑦 ) ) ∧ 𝑦 ∈ On ) → 𝑥 = ( card ‘ 𝑦 ) )
35 eleq1 ⊢ ( 𝑥 = ( card ‘ 𝑦 ) → ( 𝑥 ∈ ran card ↔ ( card ‘ 𝑦 ) ∈ ran card ) )
36 breq2 ⊢ ( 𝑥 = ( card ‘ 𝑦 ) → ( 𝐴 ≺ 𝑥 ↔ 𝐴 ≺ ( card ‘ 𝑦 ) ) )
37 35 36 anbi12d ⊢ ( 𝑥 = ( card ‘ 𝑦 ) → ( ( 𝑥 ∈ ran card ∧ 𝐴 ≺ 𝑥 ) ↔ ( ( card ‘ 𝑦 ) ∈ ran card ∧ 𝐴 ≺ ( card ‘ 𝑦 ) ) ) )
38 34 37 syl ⊢ ( ( 𝑥 = ( 𝑦 ∩ ( card ‘ 𝑦 ) ) ∧ 𝑦 ∈ On ) → ( ( 𝑥 ∈ ran card ∧ 𝐴 ≺ 𝑥 ) ↔ ( ( card ‘ 𝑦 ) ∈ ran card ∧ 𝐴 ≺ ( card ‘ 𝑦 ) ) ) )
39 28 38 sylibrd ⊢ ( ( 𝑥 = ( 𝑦 ∩ ( card ‘ 𝑦 ) ) ∧ 𝑦 ∈ On ) → ( 𝐴 ≺ 𝑦 → ( 𝑥 ∈ ran card ∧ 𝐴 ≺ 𝑥 ) ) )
40 39 expimpd ⊢ ( 𝑥 = ( 𝑦 ∩ ( card ‘ 𝑦 ) ) → ( ( 𝑦 ∈ On ∧ 𝐴 ≺ 𝑦 ) → ( 𝑥 ∈ ran card ∧ 𝐴 ≺ 𝑥 ) ) )
41 40 adantl ⊢ ( ( 𝐴 ∈ dom card ∧ 𝑥 = ( 𝑦 ∩ ( card ‘ 𝑦 ) ) ) → ( ( 𝑦 ∈ On ∧ 𝐴 ≺ 𝑦 ) → ( 𝑥 ∈ ran card ∧ 𝐴 ≺ 𝑥 ) ) )
42 inss1 ⊢ ( 𝑦 ∩ ( card ‘ 𝑦 ) ) ⊆ 𝑦
43 42 a1i ⊢ ( 𝐴 ∈ dom card → ( 𝑦 ∩ ( card ‘ 𝑦 ) ) ⊆ 𝑦 )
44 16 41 43 intabssd ⊢ ( 𝐴 ∈ dom card → ∩ { 𝑥 ∣ ( 𝑥 ∈ ran card ∧ 𝐴 ≺ 𝑥 ) } ⊆ ∩ { 𝑦 ∣ ( 𝑦 ∈ On ∧ 𝐴 ≺ 𝑦 ) } )
45 13 44 eqssd ⊢ ( 𝐴 ∈ dom card → ∩ { 𝑦 ∣ ( 𝑦 ∈ On ∧ 𝐴 ≺ 𝑦 ) } = ∩ { 𝑥 ∣ ( 𝑥 ∈ ran card ∧ 𝐴 ≺ 𝑥 ) } )
46 df-rab ⊢ { 𝑦 ∈ On ∣ 𝐴 ≺ 𝑦 } = { 𝑦 ∣ ( 𝑦 ∈ On ∧ 𝐴 ≺ 𝑦 ) }
47 46 inteqi ⊢ ∩ { 𝑦 ∈ On ∣ 𝐴 ≺ 𝑦 } = ∩ { 𝑦 ∣ ( 𝑦 ∈ On ∧ 𝐴 ≺ 𝑦 ) }
48 df-rab ⊢ { 𝑥 ∈ ran card ∣ 𝐴 ≺ 𝑥 } = { 𝑥 ∣ ( 𝑥 ∈ ran card ∧ 𝐴 ≺ 𝑥 ) }
49 48 inteqi ⊢ ∩ { 𝑥 ∈ ran card ∣ 𝐴 ≺ 𝑥 } = ∩ { 𝑥 ∣ ( 𝑥 ∈ ran card ∧ 𝐴 ≺ 𝑥 ) }
50 45 47 49 3eqtr4g ⊢ ( 𝐴 ∈ dom card → ∩ { 𝑦 ∈ On ∣ 𝐴 ≺ 𝑦 } = ∩ { 𝑥 ∈ ran card ∣ 𝐴 ≺ 𝑥 } )
51 1 50 eqtrd ⊢ ( 𝐴 ∈ dom card → ( har ‘ 𝐴 ) = ∩ { 𝑥 ∈ ran card ∣ 𝐴 ≺ 𝑥 } )