Metamath Proof Explorer


Theorem mulmoddvds

Description: If an integer is divisible by a positive integer, the product of this integer with another integer modulo the positive integer is 0. (Contributed by Alexander van der Vekens, 30-Aug-2018) (Proof shortened by AV, 18-Mar-2022)

Ref Expression
Assertion mulmoddvds
|- ( ( N e. NN /\ A e. ZZ /\ B e. ZZ ) -> ( N || A -> ( ( A x. B ) mod N ) = 0 ) )

Proof

Step Hyp Ref Expression
1 simp1
 |-  ( ( N e. NN /\ A e. ZZ /\ B e. ZZ ) -> N e. NN )
2 nnz
 |-  ( N e. NN -> N e. ZZ )
3 dvdsmultr1
 |-  ( ( N e. ZZ /\ A e. ZZ /\ B e. ZZ ) -> ( N || A -> N || ( A x. B ) ) )
4 2 3 syl3an1
 |-  ( ( N e. NN /\ A e. ZZ /\ B e. ZZ ) -> ( N || A -> N || ( A x. B ) ) )
5 dvdsmod0
 |-  ( ( N e. NN /\ N || ( A x. B ) ) -> ( ( A x. B ) mod N ) = 0 )
6 1 4 5 syl6an
 |-  ( ( N e. NN /\ A e. ZZ /\ B e. ZZ ) -> ( N || A -> ( ( A x. B ) mod N ) = 0 ) )