Metamath Proof Explorer


Theorem invginvrid

Description: Identity for a multiplication with additive and multiplicative inverses in a ring. (Contributed by AV, 18-May-2018)

Ref Expression
Hypotheses invginvrid.b 𝐵 = ( Base ‘ 𝑅 )
invginvrid.u 𝑈 = ( Unit ‘ 𝑅 )
invginvrid.n 𝑁 = ( invg𝑅 )
invginvrid.i 𝐼 = ( invr𝑅 )
invginvrid.t · = ( .r𝑅 )
Assertion invginvrid ( ( 𝑅 ∈ Ring ∧ 𝑋𝐵𝑌𝑈 ) → ( ( 𝑁𝑌 ) · ( ( 𝐼 ‘ ( 𝑁𝑌 ) ) · 𝑋 ) ) = 𝑋 )

Proof

Step Hyp Ref Expression
1 invginvrid.b 𝐵 = ( Base ‘ 𝑅 )
2 invginvrid.u 𝑈 = ( Unit ‘ 𝑅 )
3 invginvrid.n 𝑁 = ( invg𝑅 )
4 invginvrid.i 𝐼 = ( invr𝑅 )
5 invginvrid.t · = ( .r𝑅 )
6 eqid ( mulGrp ‘ 𝑅 ) = ( mulGrp ‘ 𝑅 )
7 6 ringmgp ( 𝑅 ∈ Ring → ( mulGrp ‘ 𝑅 ) ∈ Mnd )
8 7 3ad2ant1 ( ( 𝑅 ∈ Ring ∧ 𝑋𝐵𝑌𝑈 ) → ( mulGrp ‘ 𝑅 ) ∈ Mnd )
9 ringgrp ( 𝑅 ∈ Ring → 𝑅 ∈ Grp )
10 1 2 unitcl ( 𝑌𝑈𝑌𝐵 )
11 1 3 grpinvcl ( ( 𝑅 ∈ Grp ∧ 𝑌𝐵 ) → ( 𝑁𝑌 ) ∈ 𝐵 )
12 9 10 11 syl2an ( ( 𝑅 ∈ Ring ∧ 𝑌𝑈 ) → ( 𝑁𝑌 ) ∈ 𝐵 )
13 12 3adant2 ( ( 𝑅 ∈ Ring ∧ 𝑋𝐵𝑌𝑈 ) → ( 𝑁𝑌 ) ∈ 𝐵 )
14 2 3 unitnegcl ( ( 𝑅 ∈ Ring ∧ 𝑌𝑈 ) → ( 𝑁𝑌 ) ∈ 𝑈 )
15 2 4 1 ringinvcl ( ( 𝑅 ∈ Ring ∧ ( 𝑁𝑌 ) ∈ 𝑈 ) → ( 𝐼 ‘ ( 𝑁𝑌 ) ) ∈ 𝐵 )
16 14 15 syldan ( ( 𝑅 ∈ Ring ∧ 𝑌𝑈 ) → ( 𝐼 ‘ ( 𝑁𝑌 ) ) ∈ 𝐵 )
17 16 3adant2 ( ( 𝑅 ∈ Ring ∧ 𝑋𝐵𝑌𝑈 ) → ( 𝐼 ‘ ( 𝑁𝑌 ) ) ∈ 𝐵 )
18 simp2 ( ( 𝑅 ∈ Ring ∧ 𝑋𝐵𝑌𝑈 ) → 𝑋𝐵 )
19 6 1 mgpbas 𝐵 = ( Base ‘ ( mulGrp ‘ 𝑅 ) )
20 6 5 mgpplusg · = ( +g ‘ ( mulGrp ‘ 𝑅 ) )
21 19 20 mndass ( ( ( mulGrp ‘ 𝑅 ) ∈ Mnd ∧ ( ( 𝑁𝑌 ) ∈ 𝐵 ∧ ( 𝐼 ‘ ( 𝑁𝑌 ) ) ∈ 𝐵𝑋𝐵 ) ) → ( ( ( 𝑁𝑌 ) · ( 𝐼 ‘ ( 𝑁𝑌 ) ) ) · 𝑋 ) = ( ( 𝑁𝑌 ) · ( ( 𝐼 ‘ ( 𝑁𝑌 ) ) · 𝑋 ) ) )
22 21 eqcomd ( ( ( mulGrp ‘ 𝑅 ) ∈ Mnd ∧ ( ( 𝑁𝑌 ) ∈ 𝐵 ∧ ( 𝐼 ‘ ( 𝑁𝑌 ) ) ∈ 𝐵𝑋𝐵 ) ) → ( ( 𝑁𝑌 ) · ( ( 𝐼 ‘ ( 𝑁𝑌 ) ) · 𝑋 ) ) = ( ( ( 𝑁𝑌 ) · ( 𝐼 ‘ ( 𝑁𝑌 ) ) ) · 𝑋 ) )
23 8 13 17 18 22 syl13anc ( ( 𝑅 ∈ Ring ∧ 𝑋𝐵𝑌𝑈 ) → ( ( 𝑁𝑌 ) · ( ( 𝐼 ‘ ( 𝑁𝑌 ) ) · 𝑋 ) ) = ( ( ( 𝑁𝑌 ) · ( 𝐼 ‘ ( 𝑁𝑌 ) ) ) · 𝑋 ) )
24 simp1 ( ( 𝑅 ∈ Ring ∧ 𝑋𝐵𝑌𝑈 ) → 𝑅 ∈ Ring )
25 14 3adant2 ( ( 𝑅 ∈ Ring ∧ 𝑋𝐵𝑌𝑈 ) → ( 𝑁𝑌 ) ∈ 𝑈 )
26 eqid ( 1r𝑅 ) = ( 1r𝑅 )
27 2 4 5 26 unitrinv ( ( 𝑅 ∈ Ring ∧ ( 𝑁𝑌 ) ∈ 𝑈 ) → ( ( 𝑁𝑌 ) · ( 𝐼 ‘ ( 𝑁𝑌 ) ) ) = ( 1r𝑅 ) )
28 24 25 27 syl2anc ( ( 𝑅 ∈ Ring ∧ 𝑋𝐵𝑌𝑈 ) → ( ( 𝑁𝑌 ) · ( 𝐼 ‘ ( 𝑁𝑌 ) ) ) = ( 1r𝑅 ) )
29 28 oveq1d ( ( 𝑅 ∈ Ring ∧ 𝑋𝐵𝑌𝑈 ) → ( ( ( 𝑁𝑌 ) · ( 𝐼 ‘ ( 𝑁𝑌 ) ) ) · 𝑋 ) = ( ( 1r𝑅 ) · 𝑋 ) )
30 1 5 26 ringlidm ( ( 𝑅 ∈ Ring ∧ 𝑋𝐵 ) → ( ( 1r𝑅 ) · 𝑋 ) = 𝑋 )
31 30 3adant3 ( ( 𝑅 ∈ Ring ∧ 𝑋𝐵𝑌𝑈 ) → ( ( 1r𝑅 ) · 𝑋 ) = 𝑋 )
32 23 29 31 3eqtrd ( ( 𝑅 ∈ Ring ∧ 𝑋𝐵𝑌𝑈 ) → ( ( 𝑁𝑌 ) · ( ( 𝐼 ‘ ( 𝑁𝑌 ) ) · 𝑋 ) ) = 𝑋 )