Metamath Proof Explorer


Theorem cantnfub2

Description: Given a finite number of terms of the form ( (om ^o ( An ) ) .o ( Mn ) ) with distinct exponents, we may order them from largest to smallest and find the sum is less than ( om ^o suc U. ran A ) when ( Mn ) is less than _om . Lemma 5.2 of Schloeder p. 15. (Contributed by RP, 9-Feb-2025)

Ref Expression
Hypotheses cantnfub2.n ( 𝜑𝑁 ∈ ω )
cantnfub2.a ( 𝜑𝐴 : 𝑁1-1→ On )
cantnfub2.m ( 𝜑𝑀 : 𝑁 ⟶ ω )
cantnfub2.f 𝐹 = ( 𝑥 ∈ suc ran 𝐴 ↦ if ( 𝑥 ∈ ran 𝐴 , ( 𝑀 ‘ ( 𝐴𝑥 ) ) , ∅ ) )
Assertion cantnfub2 ( 𝜑 → ( suc ran 𝐴 ∈ On ∧ 𝐹 ∈ dom ( ω CNF suc ran 𝐴 ) ∧ ( ( ω CNF suc ran 𝐴 ) ‘ 𝐹 ) ∈ ( ω ↑o suc ran 𝐴 ) ) )

Proof

Step Hyp Ref Expression
1 cantnfub2.n ( 𝜑𝑁 ∈ ω )
2 cantnfub2.a ( 𝜑𝐴 : 𝑁1-1→ On )
3 cantnfub2.m ( 𝜑𝑀 : 𝑁 ⟶ ω )
4 cantnfub2.f 𝐹 = ( 𝑥 ∈ suc ran 𝐴 ↦ if ( 𝑥 ∈ ran 𝐴 , ( 𝑀 ‘ ( 𝐴𝑥 ) ) , ∅ ) )
5 f1fn ( 𝐴 : 𝑁1-1→ On → 𝐴 Fn 𝑁 )
6 2 5 syl ( 𝜑𝐴 Fn 𝑁 )
7 nnfi ( 𝑁 ∈ ω → 𝑁 ∈ Fin )
8 1 7 syl ( 𝜑𝑁 ∈ Fin )
9 fnfi ( ( 𝐴 Fn 𝑁𝑁 ∈ Fin ) → 𝐴 ∈ Fin )
10 6 8 9 syl2anc ( 𝜑𝐴 ∈ Fin )
11 rnfi ( 𝐴 ∈ Fin → ran 𝐴 ∈ Fin )
12 10 11 syl ( 𝜑 → ran 𝐴 ∈ Fin )
13 f1f ( 𝐴 : 𝑁1-1→ On → 𝐴 : 𝑁 ⟶ On )
14 2 13 syl ( 𝜑𝐴 : 𝑁 ⟶ On )
15 14 frnd ( 𝜑 → ran 𝐴 ⊆ On )
16 ssonuni ( ran 𝐴 ∈ Fin → ( ran 𝐴 ⊆ On → ran 𝐴 ∈ On ) )
17 12 15 16 sylc ( 𝜑 ran 𝐴 ∈ On )
18 onsuc ( ran 𝐴 ∈ On → suc ran 𝐴 ∈ On )
19 17 18 syl ( 𝜑 → suc ran 𝐴 ∈ On )
20 onsucuni ( ran 𝐴 ⊆ On → ran 𝐴 ⊆ suc ran 𝐴 )
21 15 20 syl ( 𝜑 → ran 𝐴 ⊆ suc ran 𝐴 )
22 f1ssr ( ( 𝐴 : 𝑁1-1→ On ∧ ran 𝐴 ⊆ suc ran 𝐴 ) → 𝐴 : 𝑁1-1→ suc ran 𝐴 )
23 2 21 22 syl2anc ( 𝜑𝐴 : 𝑁1-1→ suc ran 𝐴 )
24 19 1 23 3 4 cantnfub ( 𝜑 → ( 𝐹 ∈ dom ( ω CNF suc ran 𝐴 ) ∧ ( ( ω CNF suc ran 𝐴 ) ‘ 𝐹 ) ∈ ( ω ↑o suc ran 𝐴 ) ) )
25 3anass ( ( suc ran 𝐴 ∈ On ∧ 𝐹 ∈ dom ( ω CNF suc ran 𝐴 ) ∧ ( ( ω CNF suc ran 𝐴 ) ‘ 𝐹 ) ∈ ( ω ↑o suc ran 𝐴 ) ) ↔ ( suc ran 𝐴 ∈ On ∧ ( 𝐹 ∈ dom ( ω CNF suc ran 𝐴 ) ∧ ( ( ω CNF suc ran 𝐴 ) ‘ 𝐹 ) ∈ ( ω ↑o suc ran 𝐴 ) ) ) )
26 19 24 25 sylanbrc ( 𝜑 → ( suc ran 𝐴 ∈ On ∧ 𝐹 ∈ dom ( ω CNF suc ran 𝐴 ) ∧ ( ( ω CNF suc ran 𝐴 ) ‘ 𝐹 ) ∈ ( ω ↑o suc ran 𝐴 ) ) )