Metamath Proof Explorer


Theorem oldlim

Description: The value of the old set at a limit ordinal. (Contributed by Scott Fenton, 8-Aug-2024)

Ref Expression
Assertion oldlim ( ( Lim 𝐴𝐴𝑉 ) → ( O ‘ 𝐴 ) = ( O “ 𝐴 ) )

Proof

Step Hyp Ref Expression
1 simprl ( ( ( Lim 𝐴𝐴𝑉 ) ∧ ( 𝑐𝐴𝑥 ∈ ( M ‘ 𝑐 ) ) ) → 𝑐𝐴 )
2 limsuc ( Lim 𝐴 → ( 𝑐𝐴 ↔ suc 𝑐𝐴 ) )
3 2 ad2antrr ( ( ( Lim 𝐴𝐴𝑉 ) ∧ ( 𝑐𝐴𝑥 ∈ ( M ‘ 𝑐 ) ) ) → ( 𝑐𝐴 ↔ suc 𝑐𝐴 ) )
4 1 3 mpbid ( ( ( Lim 𝐴𝐴𝑉 ) ∧ ( 𝑐𝐴𝑥 ∈ ( M ‘ 𝑐 ) ) ) → suc 𝑐𝐴 )
5 simprr ( ( ( Lim 𝐴𝐴𝑉 ) ∧ ( 𝑐𝐴𝑥 ∈ ( M ‘ 𝑐 ) ) ) → 𝑥 ∈ ( M ‘ 𝑐 ) )
6 limord ( Lim 𝐴 → Ord 𝐴 )
7 elex ( 𝐴𝑉𝐴 ∈ V )
8 6 7 anim12i ( ( Lim 𝐴𝐴𝑉 ) → ( Ord 𝐴𝐴 ∈ V ) )
9 elon2 ( 𝐴 ∈ On ↔ ( Ord 𝐴𝐴 ∈ V ) )
10 8 9 sylibr ( ( Lim 𝐴𝐴𝑉 ) → 𝐴 ∈ On )
11 onelon ( ( 𝐴 ∈ On ∧ 𝑐𝐴 ) → 𝑐 ∈ On )
12 10 1 11 syl2an2r ( ( ( Lim 𝐴𝐴𝑉 ) ∧ ( 𝑐𝐴𝑥 ∈ ( M ‘ 𝑐 ) ) ) → 𝑐 ∈ On )
13 madeoldsuc ( 𝑐 ∈ On → ( M ‘ 𝑐 ) = ( O ‘ suc 𝑐 ) )
14 12 13 syl ( ( ( Lim 𝐴𝐴𝑉 ) ∧ ( 𝑐𝐴𝑥 ∈ ( M ‘ 𝑐 ) ) ) → ( M ‘ 𝑐 ) = ( O ‘ suc 𝑐 ) )
15 5 14 eleqtrd ( ( ( Lim 𝐴𝐴𝑉 ) ∧ ( 𝑐𝐴𝑥 ∈ ( M ‘ 𝑐 ) ) ) → 𝑥 ∈ ( O ‘ suc 𝑐 ) )
16 fveq2 ( 𝑏 = suc 𝑐 → ( O ‘ 𝑏 ) = ( O ‘ suc 𝑐 ) )
17 16 eleq2d ( 𝑏 = suc 𝑐 → ( 𝑥 ∈ ( O ‘ 𝑏 ) ↔ 𝑥 ∈ ( O ‘ suc 𝑐 ) ) )
18 17 rspcev ( ( suc 𝑐𝐴𝑥 ∈ ( O ‘ suc 𝑐 ) ) → ∃ 𝑏𝐴 𝑥 ∈ ( O ‘ 𝑏 ) )
19 4 15 18 syl2anc ( ( ( Lim 𝐴𝐴𝑉 ) ∧ ( 𝑐𝐴𝑥 ∈ ( M ‘ 𝑐 ) ) ) → ∃ 𝑏𝐴 𝑥 ∈ ( O ‘ 𝑏 ) )
20 19 expr ( ( ( Lim 𝐴𝐴𝑉 ) ∧ 𝑐𝐴 ) → ( 𝑥 ∈ ( M ‘ 𝑐 ) → ∃ 𝑏𝐴 𝑥 ∈ ( O ‘ 𝑏 ) ) )
21 20 rexlimdva ( ( Lim 𝐴𝐴𝑉 ) → ( ∃ 𝑐𝐴 𝑥 ∈ ( M ‘ 𝑐 ) → ∃ 𝑏𝐴 𝑥 ∈ ( O ‘ 𝑏 ) ) )
22 simprl ( ( ( Lim 𝐴𝐴𝑉 ) ∧ ( 𝑏𝐴𝑥 ∈ ( O ‘ 𝑏 ) ) ) → 𝑏𝐴 )
23 onelon ( ( 𝐴 ∈ On ∧ 𝑏𝐴 ) → 𝑏 ∈ On )
24 10 22 23 syl2an2r ( ( ( Lim 𝐴𝐴𝑉 ) ∧ ( 𝑏𝐴𝑥 ∈ ( O ‘ 𝑏 ) ) ) → 𝑏 ∈ On )
25 oldssmade ( 𝑏 ∈ On → ( O ‘ 𝑏 ) ⊆ ( M ‘ 𝑏 ) )
26 24 25 syl ( ( ( Lim 𝐴𝐴𝑉 ) ∧ ( 𝑏𝐴𝑥 ∈ ( O ‘ 𝑏 ) ) ) → ( O ‘ 𝑏 ) ⊆ ( M ‘ 𝑏 ) )
27 simprr ( ( ( Lim 𝐴𝐴𝑉 ) ∧ ( 𝑏𝐴𝑥 ∈ ( O ‘ 𝑏 ) ) ) → 𝑥 ∈ ( O ‘ 𝑏 ) )
28 26 27 sseldd ( ( ( Lim 𝐴𝐴𝑉 ) ∧ ( 𝑏𝐴𝑥 ∈ ( O ‘ 𝑏 ) ) ) → 𝑥 ∈ ( M ‘ 𝑏 ) )
29 fveq2 ( 𝑐 = 𝑏 → ( M ‘ 𝑐 ) = ( M ‘ 𝑏 ) )
30 29 eleq2d ( 𝑐 = 𝑏 → ( 𝑥 ∈ ( M ‘ 𝑐 ) ↔ 𝑥 ∈ ( M ‘ 𝑏 ) ) )
31 30 rspcev ( ( 𝑏𝐴𝑥 ∈ ( M ‘ 𝑏 ) ) → ∃ 𝑐𝐴 𝑥 ∈ ( M ‘ 𝑐 ) )
32 22 28 31 syl2anc ( ( ( Lim 𝐴𝐴𝑉 ) ∧ ( 𝑏𝐴𝑥 ∈ ( O ‘ 𝑏 ) ) ) → ∃ 𝑐𝐴 𝑥 ∈ ( M ‘ 𝑐 ) )
33 32 expr ( ( ( Lim 𝐴𝐴𝑉 ) ∧ 𝑏𝐴 ) → ( 𝑥 ∈ ( O ‘ 𝑏 ) → ∃ 𝑐𝐴 𝑥 ∈ ( M ‘ 𝑐 ) ) )
34 33 rexlimdva ( ( Lim 𝐴𝐴𝑉 ) → ( ∃ 𝑏𝐴 𝑥 ∈ ( O ‘ 𝑏 ) → ∃ 𝑐𝐴 𝑥 ∈ ( M ‘ 𝑐 ) ) )
35 21 34 impbid ( ( Lim 𝐴𝐴𝑉 ) → ( ∃ 𝑐𝐴 𝑥 ∈ ( M ‘ 𝑐 ) ↔ ∃ 𝑏𝐴 𝑥 ∈ ( O ‘ 𝑏 ) ) )
36 elold ( 𝐴 ∈ On → ( 𝑥 ∈ ( O ‘ 𝐴 ) ↔ ∃ 𝑐𝐴 𝑥 ∈ ( M ‘ 𝑐 ) ) )
37 10 36 syl ( ( Lim 𝐴𝐴𝑉 ) → ( 𝑥 ∈ ( O ‘ 𝐴 ) ↔ ∃ 𝑐𝐴 𝑥 ∈ ( M ‘ 𝑐 ) ) )
38 eliun ( 𝑥 𝑏𝐴 ( O ‘ 𝑏 ) ↔ ∃ 𝑏𝐴 𝑥 ∈ ( O ‘ 𝑏 ) )
39 38 a1i ( ( Lim 𝐴𝐴𝑉 ) → ( 𝑥 𝑏𝐴 ( O ‘ 𝑏 ) ↔ ∃ 𝑏𝐴 𝑥 ∈ ( O ‘ 𝑏 ) ) )
40 35 37 39 3bitr4d ( ( Lim 𝐴𝐴𝑉 ) → ( 𝑥 ∈ ( O ‘ 𝐴 ) ↔ 𝑥 𝑏𝐴 ( O ‘ 𝑏 ) ) )
41 40 eqrdv ( ( Lim 𝐴𝐴𝑉 ) → ( O ‘ 𝐴 ) = 𝑏𝐴 ( O ‘ 𝑏 ) )
42 oldf O : On ⟶ 𝒫 No
43 ffun ( O : On ⟶ 𝒫 No → Fun O )
44 funiunfv ( Fun O → 𝑏𝐴 ( O ‘ 𝑏 ) = ( O “ 𝐴 ) )
45 42 43 44 mp2b 𝑏𝐴 ( O ‘ 𝑏 ) = ( O “ 𝐴 )
46 41 45 eqtrdi ( ( Lim 𝐴𝐴𝑉 ) → ( O ‘ 𝐴 ) = ( O “ 𝐴 ) )