Metamath Proof Explorer


Theorem rngccatALTV

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