Metamath Proof Explorer


Theorem fthpropd

Description: If two categories have the same set of objects, morphisms, and compositions, then they have the same faithful functors. (Contributed by Mario Carneiro, 27-Jan-2017)

Ref Expression
Hypotheses fullpropd.1 ( 𝜑 → ( Homf𝐴 ) = ( Homf𝐵 ) )
fullpropd.2 ( 𝜑 → ( compf𝐴 ) = ( compf𝐵 ) )
fullpropd.3 ( 𝜑 → ( Homf𝐶 ) = ( Homf𝐷 ) )
fullpropd.4 ( 𝜑 → ( compf𝐶 ) = ( compf𝐷 ) )
fullpropd.a ( 𝜑𝐴𝑉 )
fullpropd.b ( 𝜑𝐵𝑉 )
fullpropd.c ( 𝜑𝐶𝑉 )
fullpropd.d ( 𝜑𝐷𝑉 )
Assertion fthpropd ( 𝜑 → ( 𝐴 Faith 𝐶 ) = ( 𝐵 Faith 𝐷 ) )

Proof

Step Hyp Ref Expression
1 fullpropd.1 ( 𝜑 → ( Homf𝐴 ) = ( Homf𝐵 ) )
2 fullpropd.2 ( 𝜑 → ( compf𝐴 ) = ( compf𝐵 ) )
3 fullpropd.3 ( 𝜑 → ( Homf𝐶 ) = ( Homf𝐷 ) )
4 fullpropd.4 ( 𝜑 → ( compf𝐶 ) = ( compf𝐷 ) )
5 fullpropd.a ( 𝜑𝐴𝑉 )
6 fullpropd.b ( 𝜑𝐵𝑉 )
7 fullpropd.c ( 𝜑𝐶𝑉 )
8 fullpropd.d ( 𝜑𝐷𝑉 )
9 relfth Rel ( 𝐴 Faith 𝐶 )
10 relfth Rel ( 𝐵 Faith 𝐷 )
11 1 2 3 4 5 6 7 8 funcpropd ( 𝜑 → ( 𝐴 Func 𝐶 ) = ( 𝐵 Func 𝐷 ) )
12 11 breqd ( 𝜑 → ( 𝑓 ( 𝐴 Func 𝐶 ) 𝑔𝑓 ( 𝐵 Func 𝐷 ) 𝑔 ) )
13 1 homfeqbas ( 𝜑 → ( Base ‘ 𝐴 ) = ( Base ‘ 𝐵 ) )
14 13 raleqdv ( 𝜑 → ( ∀ 𝑦 ∈ ( Base ‘ 𝐴 ) Fun ( 𝑥 𝑔 𝑦 ) ↔ ∀ 𝑦 ∈ ( Base ‘ 𝐵 ) Fun ( 𝑥 𝑔 𝑦 ) ) )
15 13 14 raleqbidv ( 𝜑 → ( ∀ 𝑥 ∈ ( Base ‘ 𝐴 ) ∀ 𝑦 ∈ ( Base ‘ 𝐴 ) Fun ( 𝑥 𝑔 𝑦 ) ↔ ∀ 𝑥 ∈ ( Base ‘ 𝐵 ) ∀ 𝑦 ∈ ( Base ‘ 𝐵 ) Fun ( 𝑥 𝑔 𝑦 ) ) )
16 12 15 anbi12d ( 𝜑 → ( ( 𝑓 ( 𝐴 Func 𝐶 ) 𝑔 ∧ ∀ 𝑥 ∈ ( Base ‘ 𝐴 ) ∀ 𝑦 ∈ ( Base ‘ 𝐴 ) Fun ( 𝑥 𝑔 𝑦 ) ) ↔ ( 𝑓 ( 𝐵 Func 𝐷 ) 𝑔 ∧ ∀ 𝑥 ∈ ( Base ‘ 𝐵 ) ∀ 𝑦 ∈ ( Base ‘ 𝐵 ) Fun ( 𝑥 𝑔 𝑦 ) ) ) )
17 eqid ( Base ‘ 𝐴 ) = ( Base ‘ 𝐴 )
18 17 isfth ( 𝑓 ( 𝐴 Faith 𝐶 ) 𝑔 ↔ ( 𝑓 ( 𝐴 Func 𝐶 ) 𝑔 ∧ ∀ 𝑥 ∈ ( Base ‘ 𝐴 ) ∀ 𝑦 ∈ ( Base ‘ 𝐴 ) Fun ( 𝑥 𝑔 𝑦 ) ) )
19 eqid ( Base ‘ 𝐵 ) = ( Base ‘ 𝐵 )
20 19 isfth ( 𝑓 ( 𝐵 Faith 𝐷 ) 𝑔 ↔ ( 𝑓 ( 𝐵 Func 𝐷 ) 𝑔 ∧ ∀ 𝑥 ∈ ( Base ‘ 𝐵 ) ∀ 𝑦 ∈ ( Base ‘ 𝐵 ) Fun ( 𝑥 𝑔 𝑦 ) ) )
21 16 18 20 3bitr4g ( 𝜑 → ( 𝑓 ( 𝐴 Faith 𝐶 ) 𝑔𝑓 ( 𝐵 Faith 𝐷 ) 𝑔 ) )
22 9 10 21 eqbrrdiv ( 𝜑 → ( 𝐴 Faith 𝐶 ) = ( 𝐵 Faith 𝐷 ) )