Metamath Proof Explorer


Theorem fltdvdsabdvdsc

Description: Any factor of both A and B also divides C . This establishes the validity of fltabcoprmex . (Contributed by SN, 21-Aug-2024)

Ref Expression
Hypotheses fltdvdsabdvdsc.a ( 𝜑𝐴 ∈ ℕ )
fltdvdsabdvdsc.b ( 𝜑𝐵 ∈ ℕ )
fltdvdsabdvdsc.c ( 𝜑𝐶 ∈ ℕ )
fltdvdsabdvdsc.n ( 𝜑𝑁 ∈ ℕ )
fltdvdsabdvdsc.1 ( 𝜑 → ( ( 𝐴𝑁 ) + ( 𝐵𝑁 ) ) = ( 𝐶𝑁 ) )
Assertion fltdvdsabdvdsc ( 𝜑 → ( 𝐴 gcd 𝐵 ) ∥ 𝐶 )

Proof

Step Hyp Ref Expression
1 fltdvdsabdvdsc.a ( 𝜑𝐴 ∈ ℕ )
2 fltdvdsabdvdsc.b ( 𝜑𝐵 ∈ ℕ )
3 fltdvdsabdvdsc.c ( 𝜑𝐶 ∈ ℕ )
4 fltdvdsabdvdsc.n ( 𝜑𝑁 ∈ ℕ )
5 fltdvdsabdvdsc.1 ( 𝜑 → ( ( 𝐴𝑁 ) + ( 𝐵𝑁 ) ) = ( 𝐶𝑁 ) )
6 gcdnncl ( ( 𝐴 ∈ ℕ ∧ 𝐵 ∈ ℕ ) → ( 𝐴 gcd 𝐵 ) ∈ ℕ )
7 1 2 6 syl2anc ( 𝜑 → ( 𝐴 gcd 𝐵 ) ∈ ℕ )
8 4 nnnn0d ( 𝜑𝑁 ∈ ℕ0 )
9 7 8 nnexpcld ( 𝜑 → ( ( 𝐴 gcd 𝐵 ) ↑ 𝑁 ) ∈ ℕ )
10 9 nnzd ( 𝜑 → ( ( 𝐴 gcd 𝐵 ) ↑ 𝑁 ) ∈ ℤ )
11 1 8 nnexpcld ( 𝜑 → ( 𝐴𝑁 ) ∈ ℕ )
12 11 nnzd ( 𝜑 → ( 𝐴𝑁 ) ∈ ℤ )
13 2 8 nnexpcld ( 𝜑 → ( 𝐵𝑁 ) ∈ ℕ )
14 13 nnzd ( 𝜑 → ( 𝐵𝑁 ) ∈ ℤ )
15 7 nnzd ( 𝜑 → ( 𝐴 gcd 𝐵 ) ∈ ℤ )
16 1 nnzd ( 𝜑𝐴 ∈ ℤ )
17 2 nnzd ( 𝜑𝐵 ∈ ℤ )
18 gcddvds ( ( 𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ) → ( ( 𝐴 gcd 𝐵 ) ∥ 𝐴 ∧ ( 𝐴 gcd 𝐵 ) ∥ 𝐵 ) )
19 16 17 18 syl2anc ( 𝜑 → ( ( 𝐴 gcd 𝐵 ) ∥ 𝐴 ∧ ( 𝐴 gcd 𝐵 ) ∥ 𝐵 ) )
20 19 simpld ( 𝜑 → ( 𝐴 gcd 𝐵 ) ∥ 𝐴 )
21 15 16 8 20 dvdsexpad ( 𝜑 → ( ( 𝐴 gcd 𝐵 ) ↑ 𝑁 ) ∥ ( 𝐴𝑁 ) )
22 19 simprd ( 𝜑 → ( 𝐴 gcd 𝐵 ) ∥ 𝐵 )
23 15 17 8 22 dvdsexpad ( 𝜑 → ( ( 𝐴 gcd 𝐵 ) ↑ 𝑁 ) ∥ ( 𝐵𝑁 ) )
24 10 12 14 21 23 dvds2addd ( 𝜑 → ( ( 𝐴 gcd 𝐵 ) ↑ 𝑁 ) ∥ ( ( 𝐴𝑁 ) + ( 𝐵𝑁 ) ) )
25 24 5 breqtrd ( 𝜑 → ( ( 𝐴 gcd 𝐵 ) ↑ 𝑁 ) ∥ ( 𝐶𝑁 ) )
26 dvdsexpnn ( ( ( 𝐴 gcd 𝐵 ) ∈ ℕ ∧ 𝐶 ∈ ℕ ∧ 𝑁 ∈ ℕ ) → ( ( 𝐴 gcd 𝐵 ) ∥ 𝐶 ↔ ( ( 𝐴 gcd 𝐵 ) ↑ 𝑁 ) ∥ ( 𝐶𝑁 ) ) )
27 7 3 4 26 syl3anc ( 𝜑 → ( ( 𝐴 gcd 𝐵 ) ∥ 𝐶 ↔ ( ( 𝐴 gcd 𝐵 ) ↑ 𝑁 ) ∥ ( 𝐶𝑁 ) ) )
28 25 27 mpbird ( 𝜑 → ( 𝐴 gcd 𝐵 ) ∥ 𝐶 )