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
|- ( ph -> A e. NN )
fltdvdsabdvdsc.b
|- ( ph -> B e. NN )
fltdvdsabdvdsc.c
|- ( ph -> C e. NN )
fltdvdsabdvdsc.n
|- ( ph -> N e. NN )
fltdvdsabdvdsc.1
|- ( ph -> ( ( A ^ N ) + ( B ^ N ) ) = ( C ^ N ) )
Assertion fltdvdsabdvdsc
|- ( ph -> ( A gcd B ) || C )

Proof

Step Hyp Ref Expression
1 fltdvdsabdvdsc.a
 |-  ( ph -> A e. NN )
2 fltdvdsabdvdsc.b
 |-  ( ph -> B e. NN )
3 fltdvdsabdvdsc.c
 |-  ( ph -> C e. NN )
4 fltdvdsabdvdsc.n
 |-  ( ph -> N e. NN )
5 fltdvdsabdvdsc.1
 |-  ( ph -> ( ( A ^ N ) + ( B ^ N ) ) = ( C ^ N ) )
6 gcdnncl
 |-  ( ( A e. NN /\ B e. NN ) -> ( A gcd B ) e. NN )
7 1 2 6 syl2anc
 |-  ( ph -> ( A gcd B ) e. NN )
8 4 nnnn0d
 |-  ( ph -> N e. NN0 )
9 7 8 nnexpcld
 |-  ( ph -> ( ( A gcd B ) ^ N ) e. NN )
10 9 nnzd
 |-  ( ph -> ( ( A gcd B ) ^ N ) e. ZZ )
11 1 8 nnexpcld
 |-  ( ph -> ( A ^ N ) e. NN )
12 11 nnzd
 |-  ( ph -> ( A ^ N ) e. ZZ )
13 2 8 nnexpcld
 |-  ( ph -> ( B ^ N ) e. NN )
14 13 nnzd
 |-  ( ph -> ( B ^ N ) e. ZZ )
15 7 nnzd
 |-  ( ph -> ( A gcd B ) e. ZZ )
16 1 nnzd
 |-  ( ph -> A e. ZZ )
17 2 nnzd
 |-  ( ph -> B e. ZZ )
18 gcddvds
 |-  ( ( A e. ZZ /\ B e. ZZ ) -> ( ( A gcd B ) || A /\ ( A gcd B ) || B ) )
19 16 17 18 syl2anc
 |-  ( ph -> ( ( A gcd B ) || A /\ ( A gcd B ) || B ) )
20 19 simpld
 |-  ( ph -> ( A gcd B ) || A )
21 15 16 8 20 dvdsexpad
 |-  ( ph -> ( ( A gcd B ) ^ N ) || ( A ^ N ) )
22 19 simprd
 |-  ( ph -> ( A gcd B ) || B )
23 15 17 8 22 dvdsexpad
 |-  ( ph -> ( ( A gcd B ) ^ N ) || ( B ^ N ) )
24 10 12 14 21 23 dvds2addd
 |-  ( ph -> ( ( A gcd B ) ^ N ) || ( ( A ^ N ) + ( B ^ N ) ) )
25 24 5 breqtrd
 |-  ( ph -> ( ( A gcd B ) ^ N ) || ( C ^ N ) )
26 dvdsexpnn
 |-  ( ( ( A gcd B ) e. NN /\ C e. NN /\ N e. NN ) -> ( ( A gcd B ) || C <-> ( ( A gcd B ) ^ N ) || ( C ^ N ) ) )
27 7 3 4 26 syl3anc
 |-  ( ph -> ( ( A gcd B ) || C <-> ( ( A gcd B ) ^ N ) || ( C ^ N ) ) )
28 25 27 mpbird
 |-  ( ph -> ( A gcd B ) || C )