Metamath Proof Explorer


Theorem pcmptcl

Description: Closure for the prime power map. (Contributed by Mario Carneiro, 12-Mar-2014)

Ref Expression
Hypotheses pcmpt.1 𝐹 = ( 𝑛 ∈ ℕ ↦ if ( 𝑛 ∈ ℙ , ( 𝑛𝐴 ) , 1 ) )
pcmpt.2 ( 𝜑 → ∀ 𝑛 ∈ ℙ 𝐴 ∈ ℕ0 )
Assertion pcmptcl ( 𝜑 → ( 𝐹 : ℕ ⟶ ℕ ∧ seq 1 ( · , 𝐹 ) : ℕ ⟶ ℕ ) )

Proof

Step Hyp Ref Expression
1 pcmpt.1 𝐹 = ( 𝑛 ∈ ℕ ↦ if ( 𝑛 ∈ ℙ , ( 𝑛𝐴 ) , 1 ) )
2 pcmpt.2 ( 𝜑 → ∀ 𝑛 ∈ ℙ 𝐴 ∈ ℕ0 )
3 pm2.27 ( 𝑛 ∈ ℙ → ( ( 𝑛 ∈ ℙ → 𝐴 ∈ ℕ0 ) → 𝐴 ∈ ℕ0 ) )
4 iftrue ( 𝑛 ∈ ℙ → if ( 𝑛 ∈ ℙ , ( 𝑛𝐴 ) , 1 ) = ( 𝑛𝐴 ) )
5 4 adantr ( ( 𝑛 ∈ ℙ ∧ 𝐴 ∈ ℕ0 ) → if ( 𝑛 ∈ ℙ , ( 𝑛𝐴 ) , 1 ) = ( 𝑛𝐴 ) )
6 prmnn ( 𝑛 ∈ ℙ → 𝑛 ∈ ℕ )
7 nnexpcl ( ( 𝑛 ∈ ℕ ∧ 𝐴 ∈ ℕ0 ) → ( 𝑛𝐴 ) ∈ ℕ )
8 6 7 sylan ( ( 𝑛 ∈ ℙ ∧ 𝐴 ∈ ℕ0 ) → ( 𝑛𝐴 ) ∈ ℕ )
9 5 8 eqeltrd ( ( 𝑛 ∈ ℙ ∧ 𝐴 ∈ ℕ0 ) → if ( 𝑛 ∈ ℙ , ( 𝑛𝐴 ) , 1 ) ∈ ℕ )
10 9 ex ( 𝑛 ∈ ℙ → ( 𝐴 ∈ ℕ0 → if ( 𝑛 ∈ ℙ , ( 𝑛𝐴 ) , 1 ) ∈ ℕ ) )
11 3 10 syld ( 𝑛 ∈ ℙ → ( ( 𝑛 ∈ ℙ → 𝐴 ∈ ℕ0 ) → if ( 𝑛 ∈ ℙ , ( 𝑛𝐴 ) , 1 ) ∈ ℕ ) )
12 iffalse ( ¬ 𝑛 ∈ ℙ → if ( 𝑛 ∈ ℙ , ( 𝑛𝐴 ) , 1 ) = 1 )
13 1nn 1 ∈ ℕ
14 12 13 eqeltrdi ( ¬ 𝑛 ∈ ℙ → if ( 𝑛 ∈ ℙ , ( 𝑛𝐴 ) , 1 ) ∈ ℕ )
15 14 a1d ( ¬ 𝑛 ∈ ℙ → ( ( 𝑛 ∈ ℙ → 𝐴 ∈ ℕ0 ) → if ( 𝑛 ∈ ℙ , ( 𝑛𝐴 ) , 1 ) ∈ ℕ ) )
16 11 15 pm2.61i ( ( 𝑛 ∈ ℙ → 𝐴 ∈ ℕ0 ) → if ( 𝑛 ∈ ℙ , ( 𝑛𝐴 ) , 1 ) ∈ ℕ )
17 16 a1d ( ( 𝑛 ∈ ℙ → 𝐴 ∈ ℕ0 ) → ( 𝑛 ∈ ℕ → if ( 𝑛 ∈ ℙ , ( 𝑛𝐴 ) , 1 ) ∈ ℕ ) )
18 17 ralimi2 ( ∀ 𝑛 ∈ ℙ 𝐴 ∈ ℕ0 → ∀ 𝑛 ∈ ℕ if ( 𝑛 ∈ ℙ , ( 𝑛𝐴 ) , 1 ) ∈ ℕ )
19 2 18 syl ( 𝜑 → ∀ 𝑛 ∈ ℕ if ( 𝑛 ∈ ℙ , ( 𝑛𝐴 ) , 1 ) ∈ ℕ )
20 1 fmpt ( ∀ 𝑛 ∈ ℕ if ( 𝑛 ∈ ℙ , ( 𝑛𝐴 ) , 1 ) ∈ ℕ ↔ 𝐹 : ℕ ⟶ ℕ )
21 19 20 sylib ( 𝜑𝐹 : ℕ ⟶ ℕ )
22 nnuz ℕ = ( ℤ ‘ 1 )
23 1zzd ( 𝜑 → 1 ∈ ℤ )
24 21 ffvelrnda ( ( 𝜑𝑘 ∈ ℕ ) → ( 𝐹𝑘 ) ∈ ℕ )
25 nnmulcl ( ( 𝑘 ∈ ℕ ∧ 𝑝 ∈ ℕ ) → ( 𝑘 · 𝑝 ) ∈ ℕ )
26 25 adantl ( ( 𝜑 ∧ ( 𝑘 ∈ ℕ ∧ 𝑝 ∈ ℕ ) ) → ( 𝑘 · 𝑝 ) ∈ ℕ )
27 22 23 24 26 seqf ( 𝜑 → seq 1 ( · , 𝐹 ) : ℕ ⟶ ℕ )
28 21 27 jca ( 𝜑 → ( 𝐹 : ℕ ⟶ ℕ ∧ seq 1 ( · , 𝐹 ) : ℕ ⟶ ℕ ) )