Metamath Proof Explorer


Theorem ressply1invg

Description: An element of a restricted polynomial algebra has the same group inverse. (Contributed by Thierry Arnoux, 30-Jan-2025)

Ref Expression
Hypotheses ressply.1
|- S = ( Poly1 ` R )
ressply.2
|- H = ( R |`s T )
ressply.3
|- U = ( Poly1 ` H )
ressply.4
|- B = ( Base ` U )
ressply.5
|- ( ph -> T e. ( SubRing ` R ) )
ressply1.1
|- P = ( S |`s B )
ressply1invg.1
|- ( ph -> X e. B )
Assertion ressply1invg
|- ( ph -> ( ( invg ` U ) ` X ) = ( ( invg ` P ) ` X ) )

Proof

Step Hyp Ref Expression
1 ressply.1
 |-  S = ( Poly1 ` R )
2 ressply.2
 |-  H = ( R |`s T )
3 ressply.3
 |-  U = ( Poly1 ` H )
4 ressply.4
 |-  B = ( Base ` U )
5 ressply.5
 |-  ( ph -> T e. ( SubRing ` R ) )
6 ressply1.1
 |-  P = ( S |`s B )
7 ressply1invg.1
 |-  ( ph -> X e. B )
8 1 2 3 4 5 6 ressply1bas
 |-  ( ph -> B = ( Base ` P ) )
9 1 2 3 4 5 6 ressply1add
 |-  ( ( ph /\ ( y e. B /\ X e. B ) ) -> ( y ( +g ` U ) X ) = ( y ( +g ` P ) X ) )
10 9 anassrs
 |-  ( ( ( ph /\ y e. B ) /\ X e. B ) -> ( y ( +g ` U ) X ) = ( y ( +g ` P ) X ) )
11 7 10 mpidan
 |-  ( ( ph /\ y e. B ) -> ( y ( +g ` U ) X ) = ( y ( +g ` P ) X ) )
12 eqid
 |-  ( 0g ` S ) = ( 0g ` S )
13 1 2 3 4 5 12 ressply10g
 |-  ( ph -> ( 0g ` S ) = ( 0g ` U ) )
14 1 2 3 4 subrgply1
 |-  ( T e. ( SubRing ` R ) -> B e. ( SubRing ` S ) )
15 5 14 syl
 |-  ( ph -> B e. ( SubRing ` S ) )
16 subrgrcl
 |-  ( B e. ( SubRing ` S ) -> S e. Ring )
17 ringmnd
 |-  ( S e. Ring -> S e. Mnd )
18 15 16 17 3syl
 |-  ( ph -> S e. Mnd )
19 subrgsubg
 |-  ( B e. ( SubRing ` S ) -> B e. ( SubGrp ` S ) )
20 12 subg0cl
 |-  ( B e. ( SubGrp ` S ) -> ( 0g ` S ) e. B )
21 15 19 20 3syl
 |-  ( ph -> ( 0g ` S ) e. B )
22 eqid
 |-  ( PwSer1 ` H ) = ( PwSer1 ` H )
23 eqid
 |-  ( Base ` ( PwSer1 ` H ) ) = ( Base ` ( PwSer1 ` H ) )
24 eqid
 |-  ( Base ` S ) = ( Base ` S )
25 1 2 3 4 5 22 23 24 ressply1bas2
 |-  ( ph -> B = ( ( Base ` ( PwSer1 ` H ) ) i^i ( Base ` S ) ) )
26 inss2
 |-  ( ( Base ` ( PwSer1 ` H ) ) i^i ( Base ` S ) ) C_ ( Base ` S )
27 25 26 eqsstrdi
 |-  ( ph -> B C_ ( Base ` S ) )
28 6 24 12 ress0g
 |-  ( ( S e. Mnd /\ ( 0g ` S ) e. B /\ B C_ ( Base ` S ) ) -> ( 0g ` S ) = ( 0g ` P ) )
29 18 21 27 28 syl3anc
 |-  ( ph -> ( 0g ` S ) = ( 0g ` P ) )
30 13 29 eqtr3d
 |-  ( ph -> ( 0g ` U ) = ( 0g ` P ) )
31 30 adantr
 |-  ( ( ph /\ y e. B ) -> ( 0g ` U ) = ( 0g ` P ) )
32 11 31 eqeq12d
 |-  ( ( ph /\ y e. B ) -> ( ( y ( +g ` U ) X ) = ( 0g ` U ) <-> ( y ( +g ` P ) X ) = ( 0g ` P ) ) )
33 8 32 riotaeqbidva
 |-  ( ph -> ( iota_ y e. B ( y ( +g ` U ) X ) = ( 0g ` U ) ) = ( iota_ y e. ( Base ` P ) ( y ( +g ` P ) X ) = ( 0g ` P ) ) )
34 eqid
 |-  ( +g ` U ) = ( +g ` U )
35 eqid
 |-  ( 0g ` U ) = ( 0g ` U )
36 eqid
 |-  ( invg ` U ) = ( invg ` U )
37 4 34 35 36 grpinvval
 |-  ( X e. B -> ( ( invg ` U ) ` X ) = ( iota_ y e. B ( y ( +g ` U ) X ) = ( 0g ` U ) ) )
38 7 37 syl
 |-  ( ph -> ( ( invg ` U ) ` X ) = ( iota_ y e. B ( y ( +g ` U ) X ) = ( 0g ` U ) ) )
39 7 8 eleqtrd
 |-  ( ph -> X e. ( Base ` P ) )
40 eqid
 |-  ( Base ` P ) = ( Base ` P )
41 eqid
 |-  ( +g ` P ) = ( +g ` P )
42 eqid
 |-  ( 0g ` P ) = ( 0g ` P )
43 eqid
 |-  ( invg ` P ) = ( invg ` P )
44 40 41 42 43 grpinvval
 |-  ( X e. ( Base ` P ) -> ( ( invg ` P ) ` X ) = ( iota_ y e. ( Base ` P ) ( y ( +g ` P ) X ) = ( 0g ` P ) ) )
45 39 44 syl
 |-  ( ph -> ( ( invg ` P ) ` X ) = ( iota_ y e. ( Base ` P ) ( y ( +g ` P ) X ) = ( 0g ` P ) ) )
46 33 38 45 3eqtr4d
 |-  ( ph -> ( ( invg ` U ) ` X ) = ( ( invg ` P ) ` X ) )