Metamath Proof Explorer


Theorem drgextlsp

Description: The scalar field is a subspace of a subring algebra. (Contributed by Thierry Arnoux, 17-Jul-2023)

Ref Expression
Hypotheses drgext.b 𝐵 = ( ( subringAlg ‘ 𝐸 ) ‘ 𝑈 )
drgext.1 ( 𝜑𝐸 ∈ DivRing )
drgext.2 ( 𝜑𝑈 ∈ ( SubRing ‘ 𝐸 ) )
drgext.f 𝐹 = ( 𝐸s 𝑈 )
drgext.3 ( 𝜑𝐹 ∈ DivRing )
Assertion drgextlsp ( 𝜑𝑈 ∈ ( LSubSp ‘ 𝐵 ) )

Proof

Step Hyp Ref Expression
1 drgext.b 𝐵 = ( ( subringAlg ‘ 𝐸 ) ‘ 𝑈 )
2 drgext.1 ( 𝜑𝐸 ∈ DivRing )
3 drgext.2 ( 𝜑𝑈 ∈ ( SubRing ‘ 𝐸 ) )
4 drgext.f 𝐹 = ( 𝐸s 𝑈 )
5 drgext.3 ( 𝜑𝐹 ∈ DivRing )
6 eqidd ( 𝜑 → ( Scalar ‘ 𝐵 ) = ( Scalar ‘ 𝐵 ) )
7 eqidd ( 𝜑 → ( Base ‘ ( Scalar ‘ 𝐵 ) ) = ( Base ‘ ( Scalar ‘ 𝐵 ) ) )
8 eqidd ( 𝜑 → ( Base ‘ 𝐵 ) = ( Base ‘ 𝐵 ) )
9 eqidd ( 𝜑 → ( +g𝐵 ) = ( +g𝐵 ) )
10 eqidd ( 𝜑 → ( ·𝑠𝐵 ) = ( ·𝑠𝐵 ) )
11 eqidd ( 𝜑 → ( LSubSp ‘ 𝐵 ) = ( LSubSp ‘ 𝐵 ) )
12 eqid ( Base ‘ 𝐸 ) = ( Base ‘ 𝐸 )
13 12 subrgss ( 𝑈 ∈ ( SubRing ‘ 𝐸 ) → 𝑈 ⊆ ( Base ‘ 𝐸 ) )
14 3 13 syl ( 𝜑𝑈 ⊆ ( Base ‘ 𝐸 ) )
15 1 a1i ( 𝜑𝐵 = ( ( subringAlg ‘ 𝐸 ) ‘ 𝑈 ) )
16 15 14 srabase ( 𝜑 → ( Base ‘ 𝐸 ) = ( Base ‘ 𝐵 ) )
17 14 16 sseqtrd ( 𝜑𝑈 ⊆ ( Base ‘ 𝐵 ) )
18 eqid ( 1r𝐸 ) = ( 1r𝐸 )
19 18 subrg1cl ( 𝑈 ∈ ( SubRing ‘ 𝐸 ) → ( 1r𝐸 ) ∈ 𝑈 )
20 ne0i ( ( 1r𝐸 ) ∈ 𝑈𝑈 ≠ ∅ )
21 3 19 20 3syl ( 𝜑𝑈 ≠ ∅ )
22 drnggrp ( 𝐹 ∈ DivRing → 𝐹 ∈ Grp )
23 5 22 syl ( 𝜑𝐹 ∈ Grp )
24 23 adantr ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ ( Scalar ‘ 𝐵 ) ) ∧ 𝑎𝑈𝑏𝑈 ) ) → 𝐹 ∈ Grp )
25 15 14 sravsca ( 𝜑 → ( .r𝐸 ) = ( ·𝑠𝐵 ) )
26 eqid ( .r𝐸 ) = ( .r𝐸 )
27 4 26 ressmulr ( 𝑈 ∈ ( SubRing ‘ 𝐸 ) → ( .r𝐸 ) = ( .r𝐹 ) )
28 3 27 syl ( 𝜑 → ( .r𝐸 ) = ( .r𝐹 ) )
29 25 28 eqtr3d ( 𝜑 → ( ·𝑠𝐵 ) = ( .r𝐹 ) )
30 29 oveqdr ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ ( Scalar ‘ 𝐵 ) ) ∧ 𝑎𝑈𝑏𝑈 ) ) → ( 𝑥 ( ·𝑠𝐵 ) 𝑎 ) = ( 𝑥 ( .r𝐹 ) 𝑎 ) )
31 drngring ( 𝐹 ∈ DivRing → 𝐹 ∈ Ring )
32 5 31 syl ( 𝜑𝐹 ∈ Ring )
33 32 adantr ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ ( Scalar ‘ 𝐵 ) ) ∧ 𝑎𝑈𝑏𝑈 ) ) → 𝐹 ∈ Ring )
34 simpr1 ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ ( Scalar ‘ 𝐵 ) ) ∧ 𝑎𝑈𝑏𝑈 ) ) → 𝑥 ∈ ( Base ‘ ( Scalar ‘ 𝐵 ) ) )
35 15 14 srasca ( 𝜑 → ( 𝐸s 𝑈 ) = ( Scalar ‘ 𝐵 ) )
36 4 35 syl5eq ( 𝜑𝐹 = ( Scalar ‘ 𝐵 ) )
37 36 fveq2d ( 𝜑 → ( Base ‘ 𝐹 ) = ( Base ‘ ( Scalar ‘ 𝐵 ) ) )
38 37 adantr ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ ( Scalar ‘ 𝐵 ) ) ∧ 𝑎𝑈𝑏𝑈 ) ) → ( Base ‘ 𝐹 ) = ( Base ‘ ( Scalar ‘ 𝐵 ) ) )
39 34 38 eleqtrrd ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ ( Scalar ‘ 𝐵 ) ) ∧ 𝑎𝑈𝑏𝑈 ) ) → 𝑥 ∈ ( Base ‘ 𝐹 ) )
40 simpr2 ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ ( Scalar ‘ 𝐵 ) ) ∧ 𝑎𝑈𝑏𝑈 ) ) → 𝑎𝑈 )
41 4 12 ressbas2 ( 𝑈 ⊆ ( Base ‘ 𝐸 ) → 𝑈 = ( Base ‘ 𝐹 ) )
42 14 41 syl ( 𝜑𝑈 = ( Base ‘ 𝐹 ) )
43 42 adantr ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ ( Scalar ‘ 𝐵 ) ) ∧ 𝑎𝑈𝑏𝑈 ) ) → 𝑈 = ( Base ‘ 𝐹 ) )
44 40 43 eleqtrd ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ ( Scalar ‘ 𝐵 ) ) ∧ 𝑎𝑈𝑏𝑈 ) ) → 𝑎 ∈ ( Base ‘ 𝐹 ) )
45 eqid ( Base ‘ 𝐹 ) = ( Base ‘ 𝐹 )
46 eqid ( .r𝐹 ) = ( .r𝐹 )
47 45 46 ringcl ( ( 𝐹 ∈ Ring ∧ 𝑥 ∈ ( Base ‘ 𝐹 ) ∧ 𝑎 ∈ ( Base ‘ 𝐹 ) ) → ( 𝑥 ( .r𝐹 ) 𝑎 ) ∈ ( Base ‘ 𝐹 ) )
48 33 39 44 47 syl3anc ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ ( Scalar ‘ 𝐵 ) ) ∧ 𝑎𝑈𝑏𝑈 ) ) → ( 𝑥 ( .r𝐹 ) 𝑎 ) ∈ ( Base ‘ 𝐹 ) )
49 30 48 eqeltrd ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ ( Scalar ‘ 𝐵 ) ) ∧ 𝑎𝑈𝑏𝑈 ) ) → ( 𝑥 ( ·𝑠𝐵 ) 𝑎 ) ∈ ( Base ‘ 𝐹 ) )
50 simpr3 ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ ( Scalar ‘ 𝐵 ) ) ∧ 𝑎𝑈𝑏𝑈 ) ) → 𝑏𝑈 )
51 50 43 eleqtrd ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ ( Scalar ‘ 𝐵 ) ) ∧ 𝑎𝑈𝑏𝑈 ) ) → 𝑏 ∈ ( Base ‘ 𝐹 ) )
52 eqid ( +g𝐹 ) = ( +g𝐹 )
53 45 52 grpcl ( ( 𝐹 ∈ Grp ∧ ( 𝑥 ( ·𝑠𝐵 ) 𝑎 ) ∈ ( Base ‘ 𝐹 ) ∧ 𝑏 ∈ ( Base ‘ 𝐹 ) ) → ( ( 𝑥 ( ·𝑠𝐵 ) 𝑎 ) ( +g𝐹 ) 𝑏 ) ∈ ( Base ‘ 𝐹 ) )
54 24 49 51 53 syl3anc ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ ( Scalar ‘ 𝐵 ) ) ∧ 𝑎𝑈𝑏𝑈 ) ) → ( ( 𝑥 ( ·𝑠𝐵 ) 𝑎 ) ( +g𝐹 ) 𝑏 ) ∈ ( Base ‘ 𝐹 ) )
55 15 14 sraaddg ( 𝜑 → ( +g𝐸 ) = ( +g𝐵 ) )
56 eqid ( +g𝐸 ) = ( +g𝐸 )
57 4 56 ressplusg ( 𝑈 ∈ ( SubRing ‘ 𝐸 ) → ( +g𝐸 ) = ( +g𝐹 ) )
58 3 57 syl ( 𝜑 → ( +g𝐸 ) = ( +g𝐹 ) )
59 55 58 eqtr3d ( 𝜑 → ( +g𝐵 ) = ( +g𝐹 ) )
60 59 adantr ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ ( Scalar ‘ 𝐵 ) ) ∧ 𝑎𝑈𝑏𝑈 ) ) → ( +g𝐵 ) = ( +g𝐹 ) )
61 60 oveqd ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ ( Scalar ‘ 𝐵 ) ) ∧ 𝑎𝑈𝑏𝑈 ) ) → ( ( 𝑥 ( ·𝑠𝐵 ) 𝑎 ) ( +g𝐵 ) 𝑏 ) = ( ( 𝑥 ( ·𝑠𝐵 ) 𝑎 ) ( +g𝐹 ) 𝑏 ) )
62 54 61 43 3eltr4d ( ( 𝜑 ∧ ( 𝑥 ∈ ( Base ‘ ( Scalar ‘ 𝐵 ) ) ∧ 𝑎𝑈𝑏𝑈 ) ) → ( ( 𝑥 ( ·𝑠𝐵 ) 𝑎 ) ( +g𝐵 ) 𝑏 ) ∈ 𝑈 )
63 6 7 8 9 10 11 17 21 62 islssd ( 𝜑𝑈 ∈ ( LSubSp ‘ 𝐵 ) )