Metamath Proof Explorer


Theorem catchomcl

Description: The Hom-set of an element of the base set of the category of categories for a weak universe belongs to the weak universe. Formerly part of the proof for catcoppccl . (Contributed by AV, 14-Oct-2024)

Ref Expression
Hypotheses catcbascl.c ⊢ 𝐶 = ( CatCat ‘ 𝑈 )
catcbascl.b ⊢ 𝐵 = ( Base ‘ 𝐶 )
catcbascl.u ⊢ ( 𝜑 → 𝑈 ∈ WUni )
catcbascl.x ⊢ ( 𝜑 → 𝑋 ∈ 𝐵 )
Assertion catchomcl ( 𝜑 → ( Hom ‘ 𝑋 ) ∈ 𝑈 )

Proof

Step Hyp Ref Expression
1 catcbascl.c ⊢ 𝐶 = ( CatCat ‘ 𝑈 )
2 catcbascl.b ⊢ 𝐵 = ( Base ‘ 𝐶 )
3 catcbascl.u ⊢ ( 𝜑 → 𝑈 ∈ WUni )
4 catcbascl.x ⊢ ( 𝜑 → 𝑋 ∈ 𝐵 )
5 homid ⊢ Hom = Slot ( Hom ‘ ndx )
6 1 2 3 4 5 catcslotelcl ⊢ ( 𝜑 → ( Hom ‘ 𝑋 ) ∈ 𝑈 )