Metamath Proof Explorer
Description: The category of non-unital rings is a category. (Contributed by AV, 27-Feb-2020) (New usage is discouraged.)
|
|
Ref |
Expression |
|
Hypothesis |
rngccatALTV.c |
⊢ 𝐶 = ( RngCatALTV ‘ 𝑈 ) |
|
Assertion |
rngccatALTV |
⊢ ( 𝑈 ∈ 𝑉 → 𝐶 ∈ Cat ) |
Proof
Step |
Hyp |
Ref |
Expression |
1 |
|
rngccatALTV.c |
⊢ 𝐶 = ( RngCatALTV ‘ 𝑈 ) |
2 |
|
eqid |
⊢ ( Base ‘ 𝐶 ) = ( Base ‘ 𝐶 ) |
3 |
1 2
|
rngccatidALTV |
⊢ ( 𝑈 ∈ 𝑉 → ( 𝐶 ∈ Cat ∧ ( Id ‘ 𝐶 ) = ( 𝑥 ∈ ( Base ‘ 𝐶 ) ↦ ( I ↾ ( Base ‘ 𝑥 ) ) ) ) ) |
4 |
3
|
simpld |
⊢ ( 𝑈 ∈ 𝑉 → 𝐶 ∈ Cat ) |