Metamath Proof Explorer


Theorem frlmsslss2

Description: A subset of a free module obtained by restricting the support set is a submodule. J is the set of permitted unit vectors. (Contributed by Stefan O'Rear, 5-Feb-2015) (Revised by AV, 23-Jun-2019)

Ref Expression
Hypotheses frlmsslss.y ⊢ 𝑌 = ( 𝑅 freeLMod 𝐼 )
frlmsslss.u ⊢ 𝑈 = ( LSubSp ‘ 𝑌 )
frlmsslss.b ⊢ 𝐵 = ( Base ‘ 𝑌 )
frlmsslss.z ⊢ 0 = ( 0g ‘ 𝑅 )
frlmsslss2.c ⊢ 𝐶 = { 𝑥 ∈ 𝐵 ∣ ( 𝑥 supp 0 ) ⊆ 𝐽 }
Assertion frlmsslss2 ( ( 𝑅 ∈ Ring ∧ 𝐼 ∈ 𝑉 ∧ 𝐽 ⊆ 𝐼 ) → 𝐶 ∈ 𝑈 )

Proof

Step Hyp Ref Expression
1 frlmsslss.y ⊢ 𝑌 = ( 𝑅 freeLMod 𝐼 )
2 frlmsslss.u ⊢ 𝑈 = ( LSubSp ‘ 𝑌 )
3 frlmsslss.b ⊢ 𝐵 = ( Base ‘ 𝑌 )
4 frlmsslss.z ⊢ 0 = ( 0g ‘ 𝑅 )
5 frlmsslss2.c ⊢ 𝐶 = { 𝑥 ∈ 𝐵 ∣ ( 𝑥 supp 0 ) ⊆ 𝐽 }
6 eqid ⊢ ( Base ‘ 𝑅 ) = ( Base ‘ 𝑅 )
7 1 6 3 frlmbasf ⊢ ( ( 𝐼 ∈ 𝑉 ∧ 𝑥 ∈ 𝐵 ) → 𝑥 : 𝐼 ⟶ ( Base ‘ 𝑅 ) )
8 7 3ad2antl2 ⊢ ( ( ( 𝑅 ∈ Ring ∧ 𝐼 ∈ 𝑉 ∧ 𝐽 ⊆ 𝐼 ) ∧ 𝑥 ∈ 𝐵 ) → 𝑥 : 𝐼 ⟶ ( Base ‘ 𝑅 ) )
9 8 ffnd ⊢ ( ( ( 𝑅 ∈ Ring ∧ 𝐼 ∈ 𝑉 ∧ 𝐽 ⊆ 𝐼 ) ∧ 𝑥 ∈ 𝐵 ) → 𝑥 Fn 𝐼 )
10 simpl3 ⊢ ( ( ( 𝑅 ∈ Ring ∧ 𝐼 ∈ 𝑉 ∧ 𝐽 ⊆ 𝐼 ) ∧ 𝑥 ∈ 𝐵 ) → 𝐽 ⊆ 𝐼 )
11 undif ⊢ ( 𝐽 ⊆ 𝐼 ↔ ( 𝐽 ∪ ( 𝐼 ∖ 𝐽 ) ) = 𝐼 )
12 10 11 sylib ⊢ ( ( ( 𝑅 ∈ Ring ∧ 𝐼 ∈ 𝑉 ∧ 𝐽 ⊆ 𝐼 ) ∧ 𝑥 ∈ 𝐵 ) → ( 𝐽 ∪ ( 𝐼 ∖ 𝐽 ) ) = 𝐼 )
13 12 fneq2d ⊢ ( ( ( 𝑅 ∈ Ring ∧ 𝐼 ∈ 𝑉 ∧ 𝐽 ⊆ 𝐼 ) ∧ 𝑥 ∈ 𝐵 ) → ( 𝑥 Fn ( 𝐽 ∪ ( 𝐼 ∖ 𝐽 ) ) ↔ 𝑥 Fn 𝐼 ) )
14 9 13 mpbird ⊢ ( ( ( 𝑅 ∈ Ring ∧ 𝐼 ∈ 𝑉 ∧ 𝐽 ⊆ 𝐼 ) ∧ 𝑥 ∈ 𝐵 ) → 𝑥 Fn ( 𝐽 ∪ ( 𝐼 ∖ 𝐽 ) ) )
15 simpr ⊢ ( ( ( 𝑅 ∈ Ring ∧ 𝐼 ∈ 𝑉 ∧ 𝐽 ⊆ 𝐼 ) ∧ 𝑥 ∈ 𝐵 ) → 𝑥 ∈ 𝐵 )
16 4 fvexi ⊢ 0 ∈ V
17 16 a1i ⊢ ( ( ( 𝑅 ∈ Ring ∧ 𝐼 ∈ 𝑉 ∧ 𝐽 ⊆ 𝐼 ) ∧ 𝑥 ∈ 𝐵 ) → 0 ∈ V )
18 disjdif ⊢ ( 𝐽 ∩ ( 𝐼 ∖ 𝐽 ) ) = ∅
19 18 a1i ⊢ ( ( ( 𝑅 ∈ Ring ∧ 𝐼 ∈ 𝑉 ∧ 𝐽 ⊆ 𝐼 ) ∧ 𝑥 ∈ 𝐵 ) → ( 𝐽 ∩ ( 𝐼 ∖ 𝐽 ) ) = ∅ )
20 fnsuppres ⊢ ( ( 𝑥 Fn ( 𝐽 ∪ ( 𝐼 ∖ 𝐽 ) ) ∧ ( 𝑥 ∈ 𝐵 ∧ 0 ∈ V ) ∧ ( 𝐽 ∩ ( 𝐼 ∖ 𝐽 ) ) = ∅ ) → ( ( 𝑥 supp 0 ) ⊆ 𝐽 ↔ ( 𝑥 ↾ ( 𝐼 ∖ 𝐽 ) ) = ( ( 𝐼 ∖ 𝐽 ) × { 0 } ) ) )
21 14 15 17 19 20 syl121anc ⊢ ( ( ( 𝑅 ∈ Ring ∧ 𝐼 ∈ 𝑉 ∧ 𝐽 ⊆ 𝐼 ) ∧ 𝑥 ∈ 𝐵 ) → ( ( 𝑥 supp 0 ) ⊆ 𝐽 ↔ ( 𝑥 ↾ ( 𝐼 ∖ 𝐽 ) ) = ( ( 𝐼 ∖ 𝐽 ) × { 0 } ) ) )
22 21 rabbidva ⊢ ( ( 𝑅 ∈ Ring ∧ 𝐼 ∈ 𝑉 ∧ 𝐽 ⊆ 𝐼 ) → { 𝑥 ∈ 𝐵 ∣ ( 𝑥 supp 0 ) ⊆ 𝐽 } = { 𝑥 ∈ 𝐵 ∣ ( 𝑥 ↾ ( 𝐼 ∖ 𝐽 ) ) = ( ( 𝐼 ∖ 𝐽 ) × { 0 } ) } )
23 5 22 eqtrid ⊢ ( ( 𝑅 ∈ Ring ∧ 𝐼 ∈ 𝑉 ∧ 𝐽 ⊆ 𝐼 ) → 𝐶 = { 𝑥 ∈ 𝐵 ∣ ( 𝑥 ↾ ( 𝐼 ∖ 𝐽 ) ) = ( ( 𝐼 ∖ 𝐽 ) × { 0 } ) } )
24 difssd ⊢ ( ( 𝑅 ∈ Ring ∧ 𝐼 ∈ 𝑉 ∧ 𝐽 ⊆ 𝐼 ) → ( 𝐼 ∖ 𝐽 ) ⊆ 𝐼 )
25 eqid ⊢ { 𝑥 ∈ 𝐵 ∣ ( 𝑥 ↾ ( 𝐼 ∖ 𝐽 ) ) = ( ( 𝐼 ∖ 𝐽 ) × { 0 } ) } = { 𝑥 ∈ 𝐵 ∣ ( 𝑥 ↾ ( 𝐼 ∖ 𝐽 ) ) = ( ( 𝐼 ∖ 𝐽 ) × { 0 } ) }
26 1 2 3 4 25 frlmsslss ⊢ ( ( 𝑅 ∈ Ring ∧ 𝐼 ∈ 𝑉 ∧ ( 𝐼 ∖ 𝐽 ) ⊆ 𝐼 ) → { 𝑥 ∈ 𝐵 ∣ ( 𝑥 ↾ ( 𝐼 ∖ 𝐽 ) ) = ( ( 𝐼 ∖ 𝐽 ) × { 0 } ) } ∈ 𝑈 )
27 24 26 syld3an3 ⊢ ( ( 𝑅 ∈ Ring ∧ 𝐼 ∈ 𝑉 ∧ 𝐽 ⊆ 𝐼 ) → { 𝑥 ∈ 𝐵 ∣ ( 𝑥 ↾ ( 𝐼 ∖ 𝐽 ) ) = ( ( 𝐼 ∖ 𝐽 ) × { 0 } ) } ∈ 𝑈 )
28 23 27 eqeltrd ⊢ ( ( 𝑅 ∈ Ring ∧ 𝐼 ∈ 𝑉 ∧ 𝐽 ⊆ 𝐼 ) → 𝐶 ∈ 𝑈 )