Metamath Proof Explorer


Theorem isthinc2

Description: A thin category is a category in which all hom-sets have cardinality less than or equal to the cardinality of 1o . (Contributed by Zhi Wang, 17-Sep-2024)

Ref Expression
Hypotheses isthinc.b B = Base C
isthinc.h H = Hom C
Assertion isthinc2 Could not format assertion : No typesetting found for |- ( C e. ThinCat <-> ( C e. Cat /\ A. x e. B A. y e. B ( x H y ) ~<_ 1o ) ) with typecode |-

Proof

Step Hyp Ref Expression
1 isthinc.b B = Base C
2 isthinc.h H = Hom C
3 1 2 isthinc Could not format ( C e. ThinCat <-> ( C e. Cat /\ A. x e. B A. y e. B E* f f e. ( x H y ) ) ) : No typesetting found for |- ( C e. ThinCat <-> ( C e. Cat /\ A. x e. B A. y e. B E* f f e. ( x H y ) ) ) with typecode |-
4 modom2 * f f x H y x H y 1 𝑜
5 4 2ralbii x B y B * f f x H y x B y B x H y 1 𝑜
6 5 anbi2i C Cat x B y B * f f x H y C Cat x B y B x H y 1 𝑜
7 3 6 bitri Could not format ( C e. ThinCat <-> ( C e. Cat /\ A. x e. B A. y e. B ( x H y ) ~<_ 1o ) ) : No typesetting found for |- ( C e. ThinCat <-> ( C e. Cat /\ A. x e. B A. y e. B ( x H y ) ~<_ 1o ) ) with typecode |-