Metamath Proof Explorer


Theorem lidlincl

Description: Ideals are closed under intersection. (Contributed by Thierry Arnoux, 5-Jul-2024)

Ref Expression
Hypothesis lidlincl.1 ⊢ U = LIdeal ⁡ R
Assertion lidlincl ⊢ R ∈ Ring ∧ I ∈ U ∧ J ∈ U → I ∩ J ∈ U

Proof

Step Hyp Ref Expression
1 lidlincl.1 ⊢ U = LIdeal ⁡ R
2 eqid ⊢ Base R = Base R
3 2 1 lidlacs ⊢ R ∈ Ring → U ∈ ACS ⁡ Base R
4 3 acsmred ⊢ R ∈ Ring → U ∈ Moore ⁡ Base R
5 mreincl ⊢ U ∈ Moore ⁡ Base R ∧ I ∈ U ∧ J ∈ U → I ∩ J ∈ U
6 4 5 syl3an1 ⊢ R ∈ Ring ∧ I ∈ U ∧ J ∈ U → I ∩ J ∈ U