Metamath Proof Explorer


Definition df-fth

Description: Function returning all the faithful functors from a category C to a category D . A faithful functor is a functor in which all the morphism maps G ( X , Y ) between objects X , Y e. C are injections. Definition 3.27(2) in Adamek p. 34. (Contributed by Mario Carneiro, 26-Jan-2017)

Ref Expression
Assertion df-fth Faith = ( 𝑐 ∈ Cat , 𝑑 ∈ Cat ↦ { ⟨ 𝑓 , 𝑔 ⟩ ∣ ( 𝑓 ( 𝑐 Func 𝑑 ) 𝑔 ∧ ∀ 𝑥 ∈ ( Base ‘ 𝑐 ) ∀ 𝑦 ∈ ( Base ‘ 𝑐 ) Fun ( 𝑥 𝑔 𝑦 ) ) } )

Detailed syntax breakdown

Step Hyp Ref Expression
0 cfth Faith
1 vc 𝑐
2 ccat Cat
3 vd 𝑑
4 vf 𝑓
5 vg 𝑔
6 4 cv 𝑓
7 1 cv 𝑐
8 cfunc Func
9 3 cv 𝑑
10 7 9 8 co ( 𝑐 Func 𝑑 )
11 5 cv 𝑔
12 6 11 10 wbr 𝑓 ( 𝑐 Func 𝑑 ) 𝑔
13 vx 𝑥
14 cbs Base
15 7 14 cfv ( Base ‘ 𝑐 )
16 vy 𝑦
17 13 cv 𝑥
18 16 cv 𝑦
19 17 18 11 co ( 𝑥 𝑔 𝑦 )
20 19 ccnv ( 𝑥 𝑔 𝑦 )
21 20 wfun Fun ( 𝑥 𝑔 𝑦 )
22 21 16 15 wral 𝑦 ∈ ( Base ‘ 𝑐 ) Fun ( 𝑥 𝑔 𝑦 )
23 22 13 15 wral 𝑥 ∈ ( Base ‘ 𝑐 ) ∀ 𝑦 ∈ ( Base ‘ 𝑐 ) Fun ( 𝑥 𝑔 𝑦 )
24 12 23 wa ( 𝑓 ( 𝑐 Func 𝑑 ) 𝑔 ∧ ∀ 𝑥 ∈ ( Base ‘ 𝑐 ) ∀ 𝑦 ∈ ( Base ‘ 𝑐 ) Fun ( 𝑥 𝑔 𝑦 ) )
25 24 4 5 copab { ⟨ 𝑓 , 𝑔 ⟩ ∣ ( 𝑓 ( 𝑐 Func 𝑑 ) 𝑔 ∧ ∀ 𝑥 ∈ ( Base ‘ 𝑐 ) ∀ 𝑦 ∈ ( Base ‘ 𝑐 ) Fun ( 𝑥 𝑔 𝑦 ) ) }
26 1 3 2 2 25 cmpo ( 𝑐 ∈ Cat , 𝑑 ∈ Cat ↦ { ⟨ 𝑓 , 𝑔 ⟩ ∣ ( 𝑓 ( 𝑐 Func 𝑑 ) 𝑔 ∧ ∀ 𝑥 ∈ ( Base ‘ 𝑐 ) ∀ 𝑦 ∈ ( Base ‘ 𝑐 ) Fun ( 𝑥 𝑔 𝑦 ) ) } )
27 0 26 wceq Faith = ( 𝑐 ∈ Cat , 𝑑 ∈ Cat ↦ { ⟨ 𝑓 , 𝑔 ⟩ ∣ ( 𝑓 ( 𝑐 Func 𝑑 ) 𝑔 ∧ ∀ 𝑥 ∈ ( Base ‘ 𝑐 ) ∀ 𝑦 ∈ ( Base ‘ 𝑐 ) Fun ( 𝑥 𝑔 𝑦 ) ) } )