Metamath Proof Explorer


Theorem pw2divsnegd

Description: Move negative sign inside of a power of two division. (Contributed by Scott Fenton, 8-Nov-2025)

Ref Expression
Hypotheses pw2divsnegd.1 ( 𝜑𝐴 No )
pw2divsnegd.2 ( 𝜑𝑁 ∈ ℕ0s )
Assertion pw2divsnegd ( 𝜑 → ( -us ‘ ( 𝐴 /su ( 2ss 𝑁 ) ) ) = ( ( -us𝐴 ) /su ( 2ss 𝑁 ) ) )

Proof

Step Hyp Ref Expression
1 pw2divsnegd.1 ( 𝜑𝐴 No )
2 pw2divsnegd.2 ( 𝜑𝑁 ∈ ℕ0s )
3 1 2 pw2divscld ( 𝜑 → ( 𝐴 /su ( 2ss 𝑁 ) ) ∈ No )
4 3 negsidd ( 𝜑 → ( ( 𝐴 /su ( 2ss 𝑁 ) ) +s ( -us ‘ ( 𝐴 /su ( 2ss 𝑁 ) ) ) ) = 0s )
5 2sno 2s No
6 expscl ( ( 2s No 𝑁 ∈ ℕ0s ) → ( 2ss 𝑁 ) ∈ No )
7 5 2 6 sylancr ( 𝜑 → ( 2ss 𝑁 ) ∈ No )
8 muls01 ( ( 2ss 𝑁 ) ∈ No → ( ( 2ss 𝑁 ) ·s 0s ) = 0s )
9 7 8 syl ( 𝜑 → ( ( 2ss 𝑁 ) ·s 0s ) = 0s )
10 1 negsidd ( 𝜑 → ( 𝐴 +s ( -us𝐴 ) ) = 0s )
11 9 10 eqtr4d ( 𝜑 → ( ( 2ss 𝑁 ) ·s 0s ) = ( 𝐴 +s ( -us𝐴 ) ) )
12 1 negscld ( 𝜑 → ( -us𝐴 ) ∈ No )
13 1 12 addscld ( 𝜑 → ( 𝐴 +s ( -us𝐴 ) ) ∈ No )
14 0sno 0s No
15 14 a1i ( 𝜑 → 0s No )
16 13 15 2 pw2divsmuld ( 𝜑 → ( ( ( 𝐴 +s ( -us𝐴 ) ) /su ( 2ss 𝑁 ) ) = 0s ↔ ( ( 2ss 𝑁 ) ·s 0s ) = ( 𝐴 +s ( -us𝐴 ) ) ) )
17 11 16 mpbird ( 𝜑 → ( ( 𝐴 +s ( -us𝐴 ) ) /su ( 2ss 𝑁 ) ) = 0s )
18 1 12 2 pw2divsdird ( 𝜑 → ( ( 𝐴 +s ( -us𝐴 ) ) /su ( 2ss 𝑁 ) ) = ( ( 𝐴 /su ( 2ss 𝑁 ) ) +s ( ( -us𝐴 ) /su ( 2ss 𝑁 ) ) ) )
19 4 17 18 3eqtr2rd ( 𝜑 → ( ( 𝐴 /su ( 2ss 𝑁 ) ) +s ( ( -us𝐴 ) /su ( 2ss 𝑁 ) ) ) = ( ( 𝐴 /su ( 2ss 𝑁 ) ) +s ( -us ‘ ( 𝐴 /su ( 2ss 𝑁 ) ) ) ) )
20 12 2 pw2divscld ( 𝜑 → ( ( -us𝐴 ) /su ( 2ss 𝑁 ) ) ∈ No )
21 3 negscld ( 𝜑 → ( -us ‘ ( 𝐴 /su ( 2ss 𝑁 ) ) ) ∈ No )
22 20 21 3 addscan1d ( 𝜑 → ( ( ( 𝐴 /su ( 2ss 𝑁 ) ) +s ( ( -us𝐴 ) /su ( 2ss 𝑁 ) ) ) = ( ( 𝐴 /su ( 2ss 𝑁 ) ) +s ( -us ‘ ( 𝐴 /su ( 2ss 𝑁 ) ) ) ) ↔ ( ( -us𝐴 ) /su ( 2ss 𝑁 ) ) = ( -us ‘ ( 𝐴 /su ( 2ss 𝑁 ) ) ) ) )
23 19 22 mpbid ( 𝜑 → ( ( -us𝐴 ) /su ( 2ss 𝑁 ) ) = ( -us ‘ ( 𝐴 /su ( 2ss 𝑁 ) ) ) )
24 23 eqcomd ( 𝜑 → ( -us ‘ ( 𝐴 /su ( 2ss 𝑁 ) ) ) = ( ( -us𝐴 ) /su ( 2ss 𝑁 ) ) )