Metamath Proof Explorer


Theorem mulgnn0subcl

Description: Closure of the group multiple (exponentiation) operation in a submonoid. (Contributed by Mario Carneiro, 10-Jan-2015)

Ref Expression
Hypotheses mulgnnsubcl.b
|- B = ( Base ` G )
mulgnnsubcl.t
|- .x. = ( .g ` G )
mulgnnsubcl.p
|- .+ = ( +g ` G )
mulgnnsubcl.g
|- ( ph -> G e. V )
mulgnnsubcl.s
|- ( ph -> S C_ B )
mulgnnsubcl.c
|- ( ( ph /\ x e. S /\ y e. S ) -> ( x .+ y ) e. S )
mulgnn0subcl.z
|- .0. = ( 0g ` G )
mulgnn0subcl.c
|- ( ph -> .0. e. S )
Assertion mulgnn0subcl
|- ( ( ph /\ N e. NN0 /\ X e. S ) -> ( N .x. X ) e. S )

Proof

Step Hyp Ref Expression
1 mulgnnsubcl.b
 |-  B = ( Base ` G )
2 mulgnnsubcl.t
 |-  .x. = ( .g ` G )
3 mulgnnsubcl.p
 |-  .+ = ( +g ` G )
4 mulgnnsubcl.g
 |-  ( ph -> G e. V )
5 mulgnnsubcl.s
 |-  ( ph -> S C_ B )
6 mulgnnsubcl.c
 |-  ( ( ph /\ x e. S /\ y e. S ) -> ( x .+ y ) e. S )
7 mulgnn0subcl.z
 |-  .0. = ( 0g ` G )
8 mulgnn0subcl.c
 |-  ( ph -> .0. e. S )
9 1 2 3 4 5 6 mulgnnsubcl
 |-  ( ( ph /\ N e. NN /\ X e. S ) -> ( N .x. X ) e. S )
10 9 3expa
 |-  ( ( ( ph /\ N e. NN ) /\ X e. S ) -> ( N .x. X ) e. S )
11 10 an32s
 |-  ( ( ( ph /\ X e. S ) /\ N e. NN ) -> ( N .x. X ) e. S )
12 11 3adantl2
 |-  ( ( ( ph /\ N e. NN0 /\ X e. S ) /\ N e. NN ) -> ( N .x. X ) e. S )
13 oveq1
 |-  ( N = 0 -> ( N .x. X ) = ( 0 .x. X ) )
14 5 3ad2ant1
 |-  ( ( ph /\ N e. NN0 /\ X e. S ) -> S C_ B )
15 simp3
 |-  ( ( ph /\ N e. NN0 /\ X e. S ) -> X e. S )
16 14 15 sseldd
 |-  ( ( ph /\ N e. NN0 /\ X e. S ) -> X e. B )
17 1 7 2 mulg0
 |-  ( X e. B -> ( 0 .x. X ) = .0. )
18 16 17 syl
 |-  ( ( ph /\ N e. NN0 /\ X e. S ) -> ( 0 .x. X ) = .0. )
19 13 18 sylan9eqr
 |-  ( ( ( ph /\ N e. NN0 /\ X e. S ) /\ N = 0 ) -> ( N .x. X ) = .0. )
20 8 3ad2ant1
 |-  ( ( ph /\ N e. NN0 /\ X e. S ) -> .0. e. S )
21 20 adantr
 |-  ( ( ( ph /\ N e. NN0 /\ X e. S ) /\ N = 0 ) -> .0. e. S )
22 19 21 eqeltrd
 |-  ( ( ( ph /\ N e. NN0 /\ X e. S ) /\ N = 0 ) -> ( N .x. X ) e. S )
23 simp2
 |-  ( ( ph /\ N e. NN0 /\ X e. S ) -> N e. NN0 )
24 elnn0
 |-  ( N e. NN0 <-> ( N e. NN \/ N = 0 ) )
25 23 24 sylib
 |-  ( ( ph /\ N e. NN0 /\ X e. S ) -> ( N e. NN \/ N = 0 ) )
26 12 22 25 mpjaodan
 |-  ( ( ph /\ N e. NN0 /\ X e. S ) -> ( N .x. X ) e. S )