Metamath Proof Explorer


Theorem ttrclselem1

Description: Lemma for ttrclse . Show that all finite ordinal function values of F are subsets of A . (Contributed by Scott Fenton, 31-Oct-2024)

Ref Expression
Hypothesis ttrclselem.1 𝐹 = rec ( ( 𝑏 ∈ V ↦ 𝑤𝑏 Pred ( 𝑅 , 𝐴 , 𝑤 ) ) , Pred ( 𝑅 , 𝐴 , 𝑋 ) )
Assertion ttrclselem1 ( 𝑁 ∈ ω → ( 𝐹𝑁 ) ⊆ 𝐴 )

Proof

Step Hyp Ref Expression
1 ttrclselem.1 𝐹 = rec ( ( 𝑏 ∈ V ↦ 𝑤𝑏 Pred ( 𝑅 , 𝐴 , 𝑤 ) ) , Pred ( 𝑅 , 𝐴 , 𝑋 ) )
2 nn0suc ( 𝑁 ∈ ω → ( 𝑁 = ∅ ∨ ∃ 𝑛 ∈ ω 𝑁 = suc 𝑛 ) )
3 1 fveq1i ( 𝐹𝑁 ) = ( rec ( ( 𝑏 ∈ V ↦ 𝑤𝑏 Pred ( 𝑅 , 𝐴 , 𝑤 ) ) , Pred ( 𝑅 , 𝐴 , 𝑋 ) ) ‘ 𝑁 )
4 fveq2 ( 𝑁 = ∅ → ( rec ( ( 𝑏 ∈ V ↦ 𝑤𝑏 Pred ( 𝑅 , 𝐴 , 𝑤 ) ) , Pred ( 𝑅 , 𝐴 , 𝑋 ) ) ‘ 𝑁 ) = ( rec ( ( 𝑏 ∈ V ↦ 𝑤𝑏 Pred ( 𝑅 , 𝐴 , 𝑤 ) ) , Pred ( 𝑅 , 𝐴 , 𝑋 ) ) ‘ ∅ ) )
5 3 4 eqtrid ( 𝑁 = ∅ → ( 𝐹𝑁 ) = ( rec ( ( 𝑏 ∈ V ↦ 𝑤𝑏 Pred ( 𝑅 , 𝐴 , 𝑤 ) ) , Pred ( 𝑅 , 𝐴 , 𝑋 ) ) ‘ ∅ ) )
6 rdg0g ( Pred ( 𝑅 , 𝐴 , 𝑋 ) ∈ V → ( rec ( ( 𝑏 ∈ V ↦ 𝑤𝑏 Pred ( 𝑅 , 𝐴 , 𝑤 ) ) , Pred ( 𝑅 , 𝐴 , 𝑋 ) ) ‘ ∅ ) = Pred ( 𝑅 , 𝐴 , 𝑋 ) )
7 predss Pred ( 𝑅 , 𝐴 , 𝑋 ) ⊆ 𝐴
8 6 7 eqsstrdi ( Pred ( 𝑅 , 𝐴 , 𝑋 ) ∈ V → ( rec ( ( 𝑏 ∈ V ↦ 𝑤𝑏 Pred ( 𝑅 , 𝐴 , 𝑤 ) ) , Pred ( 𝑅 , 𝐴 , 𝑋 ) ) ‘ ∅ ) ⊆ 𝐴 )
9 rdg0n ( ¬ Pred ( 𝑅 , 𝐴 , 𝑋 ) ∈ V → ( rec ( ( 𝑏 ∈ V ↦ 𝑤𝑏 Pred ( 𝑅 , 𝐴 , 𝑤 ) ) , Pred ( 𝑅 , 𝐴 , 𝑋 ) ) ‘ ∅ ) = ∅ )
10 0ss ∅ ⊆ 𝐴
11 9 10 eqsstrdi ( ¬ Pred ( 𝑅 , 𝐴 , 𝑋 ) ∈ V → ( rec ( ( 𝑏 ∈ V ↦ 𝑤𝑏 Pred ( 𝑅 , 𝐴 , 𝑤 ) ) , Pred ( 𝑅 , 𝐴 , 𝑋 ) ) ‘ ∅ ) ⊆ 𝐴 )
12 8 11 pm2.61i ( rec ( ( 𝑏 ∈ V ↦ 𝑤𝑏 Pred ( 𝑅 , 𝐴 , 𝑤 ) ) , Pred ( 𝑅 , 𝐴 , 𝑋 ) ) ‘ ∅ ) ⊆ 𝐴
13 5 12 eqsstrdi ( 𝑁 = ∅ → ( 𝐹𝑁 ) ⊆ 𝐴 )
14 nnon ( 𝑛 ∈ ω → 𝑛 ∈ On )
15 nfcv 𝑏 Pred ( 𝑅 , 𝐴 , 𝑋 )
16 nfcv 𝑏 𝑛
17 nfmpt1 𝑏 ( 𝑏 ∈ V ↦ 𝑤𝑏 Pred ( 𝑅 , 𝐴 , 𝑤 ) )
18 17 15 nfrdg 𝑏 rec ( ( 𝑏 ∈ V ↦ 𝑤𝑏 Pred ( 𝑅 , 𝐴 , 𝑤 ) ) , Pred ( 𝑅 , 𝐴 , 𝑋 ) )
19 1 18 nfcxfr 𝑏 𝐹
20 19 16 nffv 𝑏 ( 𝐹𝑛 )
21 nfcv 𝑏 Pred ( 𝑅 , 𝐴 , 𝑡 )
22 20 21 nfiun 𝑏 𝑡 ∈ ( 𝐹𝑛 ) Pred ( 𝑅 , 𝐴 , 𝑡 )
23 predeq3 ( 𝑤 = 𝑡 → Pred ( 𝑅 , 𝐴 , 𝑤 ) = Pred ( 𝑅 , 𝐴 , 𝑡 ) )
24 23 cbviunv 𝑤𝑏 Pred ( 𝑅 , 𝐴 , 𝑤 ) = 𝑡𝑏 Pred ( 𝑅 , 𝐴 , 𝑡 )
25 iuneq1 ( 𝑏 = ( 𝐹𝑛 ) → 𝑡𝑏 Pred ( 𝑅 , 𝐴 , 𝑡 ) = 𝑡 ∈ ( 𝐹𝑛 ) Pred ( 𝑅 , 𝐴 , 𝑡 ) )
26 24 25 eqtrid ( 𝑏 = ( 𝐹𝑛 ) → 𝑤𝑏 Pred ( 𝑅 , 𝐴 , 𝑤 ) = 𝑡 ∈ ( 𝐹𝑛 ) Pred ( 𝑅 , 𝐴 , 𝑡 ) )
27 15 16 22 1 26 rdgsucmptf ( ( 𝑛 ∈ On ∧ 𝑡 ∈ ( 𝐹𝑛 ) Pred ( 𝑅 , 𝐴 , 𝑡 ) ∈ V ) → ( 𝐹 ‘ suc 𝑛 ) = 𝑡 ∈ ( 𝐹𝑛 ) Pred ( 𝑅 , 𝐴 , 𝑡 ) )
28 iunss ( 𝑡 ∈ ( 𝐹𝑛 ) Pred ( 𝑅 , 𝐴 , 𝑡 ) ⊆ 𝐴 ↔ ∀ 𝑡 ∈ ( 𝐹𝑛 ) Pred ( 𝑅 , 𝐴 , 𝑡 ) ⊆ 𝐴 )
29 predss Pred ( 𝑅 , 𝐴 , 𝑡 ) ⊆ 𝐴
30 29 a1i ( 𝑡 ∈ ( 𝐹𝑛 ) → Pred ( 𝑅 , 𝐴 , 𝑡 ) ⊆ 𝐴 )
31 28 30 mprgbir 𝑡 ∈ ( 𝐹𝑛 ) Pred ( 𝑅 , 𝐴 , 𝑡 ) ⊆ 𝐴
32 27 31 eqsstrdi ( ( 𝑛 ∈ On ∧ 𝑡 ∈ ( 𝐹𝑛 ) Pred ( 𝑅 , 𝐴 , 𝑡 ) ∈ V ) → ( 𝐹 ‘ suc 𝑛 ) ⊆ 𝐴 )
33 14 32 sylan ( ( 𝑛 ∈ ω ∧ 𝑡 ∈ ( 𝐹𝑛 ) Pred ( 𝑅 , 𝐴 , 𝑡 ) ∈ V ) → ( 𝐹 ‘ suc 𝑛 ) ⊆ 𝐴 )
34 15 16 22 1 26 rdgsucmptnf ( ¬ 𝑡 ∈ ( 𝐹𝑛 ) Pred ( 𝑅 , 𝐴 , 𝑡 ) ∈ V → ( 𝐹 ‘ suc 𝑛 ) = ∅ )
35 34 10 eqsstrdi ( ¬ 𝑡 ∈ ( 𝐹𝑛 ) Pred ( 𝑅 , 𝐴 , 𝑡 ) ∈ V → ( 𝐹 ‘ suc 𝑛 ) ⊆ 𝐴 )
36 35 adantl ( ( 𝑛 ∈ ω ∧ ¬ 𝑡 ∈ ( 𝐹𝑛 ) Pred ( 𝑅 , 𝐴 , 𝑡 ) ∈ V ) → ( 𝐹 ‘ suc 𝑛 ) ⊆ 𝐴 )
37 33 36 pm2.61dan ( 𝑛 ∈ ω → ( 𝐹 ‘ suc 𝑛 ) ⊆ 𝐴 )
38 fveq2 ( 𝑁 = suc 𝑛 → ( 𝐹𝑁 ) = ( 𝐹 ‘ suc 𝑛 ) )
39 38 sseq1d ( 𝑁 = suc 𝑛 → ( ( 𝐹𝑁 ) ⊆ 𝐴 ↔ ( 𝐹 ‘ suc 𝑛 ) ⊆ 𝐴 ) )
40 37 39 syl5ibrcom ( 𝑛 ∈ ω → ( 𝑁 = suc 𝑛 → ( 𝐹𝑁 ) ⊆ 𝐴 ) )
41 40 rexlimiv ( ∃ 𝑛 ∈ ω 𝑁 = suc 𝑛 → ( 𝐹𝑁 ) ⊆ 𝐴 )
42 13 41 jaoi ( ( 𝑁 = ∅ ∨ ∃ 𝑛 ∈ ω 𝑁 = suc 𝑛 ) → ( 𝐹𝑁 ) ⊆ 𝐴 )
43 2 42 syl ( 𝑁 ∈ ω → ( 𝐹𝑁 ) ⊆ 𝐴 )