Metamath Proof Explorer


Theorem ndvdsp1

Description: Special case of ndvdsadd . If an integer D greater than 1 divides N , it does not divide N + 1 . (Contributed by Paul Chapman, 31-Mar-2011)

Ref Expression
Assertion ndvdsp1
|- ( ( N e. ZZ /\ D e. NN /\ 1 < D ) -> ( D || N -> -. D || ( N + 1 ) ) )

Proof

Step Hyp Ref Expression
1 1nn
 |-  1 e. NN
2 1 jctl
 |-  ( 1 < D -> ( 1 e. NN /\ 1 < D ) )
3 ndvdsadd
 |-  ( ( N e. ZZ /\ D e. NN /\ ( 1 e. NN /\ 1 < D ) ) -> ( D || N -> -. D || ( N + 1 ) ) )
4 2 3 syl3an3
 |-  ( ( N e. ZZ /\ D e. NN /\ 1 < D ) -> ( D || N -> -. D || ( N + 1 ) ) )