Metamath Proof Explorer


Theorem subsubmgm

Description: A submagma of a submagma is a submagma. (Contributed by AV, 26-Feb-2020)

Ref Expression
Hypothesis subsubmgm.h
|- H = ( G |`s S )
Assertion subsubmgm
|- ( S e. ( SubMgm ` G ) -> ( A e. ( SubMgm ` H ) <-> ( A e. ( SubMgm ` G ) /\ A C_ S ) ) )

Proof

Step Hyp Ref Expression
1 subsubmgm.h
 |-  H = ( G |`s S )
2 eqid
 |-  ( Base ` H ) = ( Base ` H )
3 2 submgmss
 |-  ( A e. ( SubMgm ` H ) -> A C_ ( Base ` H ) )
4 3 adantl
 |-  ( ( S e. ( SubMgm ` G ) /\ A e. ( SubMgm ` H ) ) -> A C_ ( Base ` H ) )
5 1 submgmbas
 |-  ( S e. ( SubMgm ` G ) -> S = ( Base ` H ) )
6 5 adantr
 |-  ( ( S e. ( SubMgm ` G ) /\ A e. ( SubMgm ` H ) ) -> S = ( Base ` H ) )
7 4 6 sseqtrrd
 |-  ( ( S e. ( SubMgm ` G ) /\ A e. ( SubMgm ` H ) ) -> A C_ S )
8 eqid
 |-  ( Base ` G ) = ( Base ` G )
9 8 submgmss
 |-  ( S e. ( SubMgm ` G ) -> S C_ ( Base ` G ) )
10 9 adantr
 |-  ( ( S e. ( SubMgm ` G ) /\ A e. ( SubMgm ` H ) ) -> S C_ ( Base ` G ) )
11 7 10 sstrd
 |-  ( ( S e. ( SubMgm ` G ) /\ A e. ( SubMgm ` H ) ) -> A C_ ( Base ` G ) )
12 1 oveq1i
 |-  ( H |`s A ) = ( ( G |`s S ) |`s A )
13 ressabs
 |-  ( ( S e. ( SubMgm ` G ) /\ A C_ S ) -> ( ( G |`s S ) |`s A ) = ( G |`s A ) )
14 12 13 syl5eq
 |-  ( ( S e. ( SubMgm ` G ) /\ A C_ S ) -> ( H |`s A ) = ( G |`s A ) )
15 7 14 syldan
 |-  ( ( S e. ( SubMgm ` G ) /\ A e. ( SubMgm ` H ) ) -> ( H |`s A ) = ( G |`s A ) )
16 eqid
 |-  ( H |`s A ) = ( H |`s A )
17 16 submgmmgm
 |-  ( A e. ( SubMgm ` H ) -> ( H |`s A ) e. Mgm )
18 17 adantl
 |-  ( ( S e. ( SubMgm ` G ) /\ A e. ( SubMgm ` H ) ) -> ( H |`s A ) e. Mgm )
19 15 18 eqeltrrd
 |-  ( ( S e. ( SubMgm ` G ) /\ A e. ( SubMgm ` H ) ) -> ( G |`s A ) e. Mgm )
20 submgmrcl
 |-  ( S e. ( SubMgm ` G ) -> G e. Mgm )
21 20 adantr
 |-  ( ( S e. ( SubMgm ` G ) /\ A e. ( SubMgm ` H ) ) -> G e. Mgm )
22 eqid
 |-  ( G |`s A ) = ( G |`s A )
23 8 22 issubmgm2
 |-  ( G e. Mgm -> ( A e. ( SubMgm ` G ) <-> ( A C_ ( Base ` G ) /\ ( G |`s A ) e. Mgm ) ) )
24 21 23 syl
 |-  ( ( S e. ( SubMgm ` G ) /\ A e. ( SubMgm ` H ) ) -> ( A e. ( SubMgm ` G ) <-> ( A C_ ( Base ` G ) /\ ( G |`s A ) e. Mgm ) ) )
25 11 19 24 mpbir2and
 |-  ( ( S e. ( SubMgm ` G ) /\ A e. ( SubMgm ` H ) ) -> A e. ( SubMgm ` G ) )
26 25 7 jca
 |-  ( ( S e. ( SubMgm ` G ) /\ A e. ( SubMgm ` H ) ) -> ( A e. ( SubMgm ` G ) /\ A C_ S ) )
27 simprr
 |-  ( ( S e. ( SubMgm ` G ) /\ ( A e. ( SubMgm ` G ) /\ A C_ S ) ) -> A C_ S )
28 5 adantr
 |-  ( ( S e. ( SubMgm ` G ) /\ ( A e. ( SubMgm ` G ) /\ A C_ S ) ) -> S = ( Base ` H ) )
29 27 28 sseqtrd
 |-  ( ( S e. ( SubMgm ` G ) /\ ( A e. ( SubMgm ` G ) /\ A C_ S ) ) -> A C_ ( Base ` H ) )
30 14 adantrl
 |-  ( ( S e. ( SubMgm ` G ) /\ ( A e. ( SubMgm ` G ) /\ A C_ S ) ) -> ( H |`s A ) = ( G |`s A ) )
31 22 submgmmgm
 |-  ( A e. ( SubMgm ` G ) -> ( G |`s A ) e. Mgm )
32 31 ad2antrl
 |-  ( ( S e. ( SubMgm ` G ) /\ ( A e. ( SubMgm ` G ) /\ A C_ S ) ) -> ( G |`s A ) e. Mgm )
33 30 32 eqeltrd
 |-  ( ( S e. ( SubMgm ` G ) /\ ( A e. ( SubMgm ` G ) /\ A C_ S ) ) -> ( H |`s A ) e. Mgm )
34 1 submgmmgm
 |-  ( S e. ( SubMgm ` G ) -> H e. Mgm )
35 34 adantr
 |-  ( ( S e. ( SubMgm ` G ) /\ ( A e. ( SubMgm ` G ) /\ A C_ S ) ) -> H e. Mgm )
36 2 16 issubmgm2
 |-  ( H e. Mgm -> ( A e. ( SubMgm ` H ) <-> ( A C_ ( Base ` H ) /\ ( H |`s A ) e. Mgm ) ) )
37 35 36 syl
 |-  ( ( S e. ( SubMgm ` G ) /\ ( A e. ( SubMgm ` G ) /\ A C_ S ) ) -> ( A e. ( SubMgm ` H ) <-> ( A C_ ( Base ` H ) /\ ( H |`s A ) e. Mgm ) ) )
38 29 33 37 mpbir2and
 |-  ( ( S e. ( SubMgm ` G ) /\ ( A e. ( SubMgm ` G ) /\ A C_ S ) ) -> A e. ( SubMgm ` H ) )
39 26 38 impbida
 |-  ( S e. ( SubMgm ` G ) -> ( A e. ( SubMgm ` H ) <-> ( A e. ( SubMgm ` G ) /\ A C_ S ) ) )