Metamath Proof Explorer

Theorem isfull2

Description: Equivalent condition for a full functor. (Contributed by Mario Carneiro, 27-Jan-2017)

Ref Expression
Hypotheses isfull.b ⊢ 𝐵 = ( Base ‘ 𝐶 )
isfull.j ⊢ 𝐽 = ( Hom ‘ 𝐷 )
isfull.h ⊢ 𝐻 = ( Hom ‘ 𝐶 )
Assertion isfull2 ( 𝐹 ( 𝐶 Full 𝐷 ) 𝐺 ↔ ( 𝐹 ( 𝐶 Func 𝐷 ) 𝐺 ∧ ∀ 𝑥 ∈ 𝐵 ∀ 𝑦 ∈ 𝐵 ( 𝑥 𝐺 𝑦 ) : ( 𝑥 𝐻 𝑦 ) –onto→ ( ( 𝐹 ‘ 𝑥 ) 𝐽 ( 𝐹 ‘ 𝑦 ) ) ) )

Proof

Step Hyp Ref Expression
1 isfull.b ⊢ 𝐵 = ( Base ‘ 𝐶 )
2 isfull.j ⊢ 𝐽 = ( Hom ‘ 𝐷 )
3 isfull.h ⊢ 𝐻 = ( Hom ‘ 𝐶 )
4 1 2 isfull ⊢ ( 𝐹 ( 𝐶 Full 𝐷 ) 𝐺 ↔ ( 𝐹 ( 𝐶 Func 𝐷 ) 𝐺 ∧ ∀ 𝑥 ∈ 𝐵 ∀ 𝑦 ∈ 𝐵 ran ( 𝑥 𝐺 𝑦 ) = ( ( 𝐹 ‘ 𝑥 ) 𝐽 ( 𝐹 ‘ 𝑦 ) ) ) )
5 simpll ⊢ ( ( ( 𝐹 ( 𝐶 Func 𝐷 ) 𝐺 ∧ 𝑥 ∈ 𝐵 ) ∧ 𝑦 ∈ 𝐵 ) → 𝐹 ( 𝐶 Func 𝐷 ) 𝐺 )
6 simplr ⊢ ( ( ( 𝐹 ( 𝐶 Func 𝐷 ) 𝐺 ∧ 𝑥 ∈ 𝐵 ) ∧ 𝑦 ∈ 𝐵 ) → 𝑥 ∈ 𝐵 )
7 simpr ⊢ ( ( ( 𝐹 ( 𝐶 Func 𝐷 ) 𝐺 ∧ 𝑥 ∈ 𝐵 ) ∧ 𝑦 ∈ 𝐵 ) → 𝑦 ∈ 𝐵 )
8 1 3 2 5 6 7 funcf2 ⊢ ( ( ( 𝐹 ( 𝐶 Func 𝐷 ) 𝐺 ∧ 𝑥 ∈ 𝐵 ) ∧ 𝑦 ∈ 𝐵 ) → ( 𝑥 𝐺 𝑦 ) : ( 𝑥 𝐻 𝑦 ) ⟶ ( ( 𝐹 ‘ 𝑥 ) 𝐽 ( 𝐹 ‘ 𝑦 ) ) )
9 ffn ⊢ ( ( 𝑥 𝐺 𝑦 ) : ( 𝑥 𝐻 𝑦 ) ⟶ ( ( 𝐹 ‘ 𝑥 ) 𝐽 ( 𝐹 ‘ 𝑦 ) ) → ( 𝑥 𝐺 𝑦 ) Fn ( 𝑥 𝐻 𝑦 ) )
10 df-fo ⊢ ( ( 𝑥 𝐺 𝑦 ) : ( 𝑥 𝐻 𝑦 ) –onto→ ( ( 𝐹 ‘ 𝑥 ) 𝐽 ( 𝐹 ‘ 𝑦 ) ) ↔ ( ( 𝑥 𝐺 𝑦 ) Fn ( 𝑥 𝐻 𝑦 ) ∧ ran ( 𝑥 𝐺 𝑦 ) = ( ( 𝐹 ‘ 𝑥 ) 𝐽 ( 𝐹 ‘ 𝑦 ) ) ) )
11 10 baib ⊢ ( ( 𝑥 𝐺 𝑦 ) Fn ( 𝑥 𝐻 𝑦 ) → ( ( 𝑥 𝐺 𝑦 ) : ( 𝑥 𝐻 𝑦 ) –onto→ ( ( 𝐹 ‘ 𝑥 ) 𝐽 ( 𝐹 ‘ 𝑦 ) ) ↔ ran ( 𝑥 𝐺 𝑦 ) = ( ( 𝐹 ‘ 𝑥 ) 𝐽 ( 𝐹 ‘ 𝑦 ) ) ) )
12 8 9 11 3syl ⊢ ( ( ( 𝐹 ( 𝐶 Func 𝐷 ) 𝐺 ∧ 𝑥 ∈ 𝐵 ) ∧ 𝑦 ∈ 𝐵 ) → ( ( 𝑥 𝐺 𝑦 ) : ( 𝑥 𝐻 𝑦 ) –onto→ ( ( 𝐹 ‘ 𝑥 ) 𝐽 ( 𝐹 ‘ 𝑦 ) ) ↔ ran ( 𝑥 𝐺 𝑦 ) = ( ( 𝐹 ‘ 𝑥 ) 𝐽 ( 𝐹 ‘ 𝑦 ) ) ) )
13 12 ralbidva ⊢ ( ( 𝐹 ( 𝐶 Func 𝐷 ) 𝐺 ∧ 𝑥 ∈ 𝐵 ) → ( ∀ 𝑦 ∈ 𝐵 ( 𝑥 𝐺 𝑦 ) : ( 𝑥 𝐻 𝑦 ) –onto→ ( ( 𝐹 ‘ 𝑥 ) 𝐽 ( 𝐹 ‘ 𝑦 ) ) ↔ ∀ 𝑦 ∈ 𝐵 ran ( 𝑥 𝐺 𝑦 ) = ( ( 𝐹 ‘ 𝑥 ) 𝐽 ( 𝐹 ‘ 𝑦 ) ) ) )
14 13 ralbidva ⊢ ( 𝐹 ( 𝐶 Func 𝐷 ) 𝐺 → ( ∀ 𝑥 ∈ 𝐵 ∀ 𝑦 ∈ 𝐵 ( 𝑥 𝐺 𝑦 ) : ( 𝑥 𝐻 𝑦 ) –onto→ ( ( 𝐹 ‘ 𝑥 ) 𝐽 ( 𝐹 ‘ 𝑦 ) ) ↔ ∀ 𝑥 ∈ 𝐵 ∀ 𝑦 ∈ 𝐵 ran ( 𝑥 𝐺 𝑦 ) = ( ( 𝐹 ‘ 𝑥 ) 𝐽 ( 𝐹 ‘ 𝑦 ) ) ) )
15 14 pm5.32i ⊢ ( ( 𝐹 ( 𝐶 Func 𝐷 ) 𝐺 ∧ ∀ 𝑥 ∈ 𝐵 ∀ 𝑦 ∈ 𝐵 ( 𝑥 𝐺 𝑦 ) : ( 𝑥 𝐻 𝑦 ) –onto→ ( ( 𝐹 ‘ 𝑥 ) 𝐽 ( 𝐹 ‘ 𝑦 ) ) ) ↔ ( 𝐹 ( 𝐶 Func 𝐷 ) 𝐺 ∧ ∀ 𝑥 ∈ 𝐵 ∀ 𝑦 ∈ 𝐵 ran ( 𝑥 𝐺 𝑦 ) = ( ( 𝐹 ‘ 𝑥 ) 𝐽 ( 𝐹 ‘ 𝑦 ) ) ) )
16 4 15 bitr4i ⊢ ( 𝐹 ( 𝐶 Full 𝐷 ) 𝐺 ↔ ( 𝐹 ( 𝐶 Func 𝐷 ) 𝐺 ∧ ∀ 𝑥 ∈ 𝐵 ∀ 𝑦 ∈ 𝐵 ( 𝑥 𝐺 𝑦 ) : ( 𝑥 𝐻 𝑦 ) –onto→ ( ( 𝐹 ‘ 𝑥 ) 𝐽 ( 𝐹 ‘ 𝑦 ) ) ) )