Metamath Proof Explorer


Theorem pw2divscld

Description: Division closure for powers of two. (Contributed by Scott Fenton, 7-Nov-2025)

Ref Expression
Hypotheses pw2divscld.1 ( 𝜑𝐴 No )
pw2divscld.2 ( 𝜑𝑁 ∈ ℕ0s )
Assertion pw2divscld ( 𝜑 → ( 𝐴 /su ( 2ss 𝑁 ) ) ∈ No )

Proof

Step Hyp Ref Expression
1 pw2divscld.1 ( 𝜑𝐴 No )
2 pw2divscld.2 ( 𝜑𝑁 ∈ ℕ0s )
3 2sno 2s No
4 expscl ( ( 2s No 𝑁 ∈ ℕ0s ) → ( 2ss 𝑁 ) ∈ No )
5 3 2 4 sylancr ( 𝜑 → ( 2ss 𝑁 ) ∈ No )
6 2ne0s 2s ≠ 0s
7 expsne0 ( ( 2s No ∧ 2s ≠ 0s𝑁 ∈ ℕ0s ) → ( 2ss 𝑁 ) ≠ 0s )
8 3 6 2 7 mp3an12i ( 𝜑 → ( 2ss 𝑁 ) ≠ 0s )
9 pw2recs ( 𝑁 ∈ ℕ0s → ∃ 𝑥 No ( ( 2ss 𝑁 ) ·s 𝑥 ) = 1s )
10 2 9 syl ( 𝜑 → ∃ 𝑥 No ( ( 2ss 𝑁 ) ·s 𝑥 ) = 1s )
11 1 5 8 10 divsclwd ( 𝜑 → ( 𝐴 /su ( 2ss 𝑁 ) ) ∈ No )