MPE Home Metamath Proof Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  MPE Home  >  Th. List  >  catidd Structured version   Visualization version   GIF version

Theorem catidd 17641
Description: Deduce the identity arrow in a category. (Contributed by Mario Carneiro, 3-Jan-2017.)
Hypotheses
Ref Expression
catidd.b (𝜑𝐵 = (Base‘𝐶))
catidd.h (𝜑𝐻 = (Hom ‘𝐶))
catidd.o (𝜑· = (comp‘𝐶))
catidd.c (𝜑𝐶 ∈ Cat)
catidd.1 ((𝜑𝑥𝐵) → 1 ∈ (𝑥𝐻𝑥))
catidd.2 ((𝜑 ∧ (𝑥𝐵𝑦𝐵𝑓 ∈ (𝑦𝐻𝑥))) → ( 1 (⟨𝑦, 𝑥· 𝑥)𝑓) = 𝑓)
catidd.3 ((𝜑 ∧ (𝑥𝐵𝑦𝐵𝑓 ∈ (𝑥𝐻𝑦))) → (𝑓(⟨𝑥, 𝑥· 𝑦) 1 ) = 𝑓)
Assertion
Ref Expression
catidd (𝜑 → (Id‘𝐶) = (𝑥𝐵1 ))
Distinct variable groups:   𝑦,𝑓, 1   𝑥,𝐵   𝑥,𝑓,𝐶,𝑦   𝜑,𝑓,𝑥,𝑦
Allowed substitution hints:   𝐵(𝑦,𝑓)   · (𝑥,𝑦,𝑓)   1 (𝑥)   𝐻(𝑥,𝑦,𝑓)

Proof of Theorem catidd
Dummy variable 𝑔 is distinct from all other variables.
StepHypRef Expression
1 catidd.2 . . . . . . . . . . 11 ((𝜑 ∧ (𝑥𝐵𝑦𝐵𝑓 ∈ (𝑦𝐻𝑥))) → ( 1 (⟨𝑦, 𝑥· 𝑥)𝑓) = 𝑓)
21ex 412 . . . . . . . . . 10 (𝜑 → ((𝑥𝐵𝑦𝐵𝑓 ∈ (𝑦𝐻𝑥)) → ( 1 (⟨𝑦, 𝑥· 𝑥)𝑓) = 𝑓))
3 catidd.b . . . . . . . . . . . 12 (𝜑𝐵 = (Base‘𝐶))
43eleq2d 2814 . . . . . . . . . . 11 (𝜑 → (𝑥𝐵𝑥 ∈ (Base‘𝐶)))
53eleq2d 2814 . . . . . . . . . . 11 (𝜑 → (𝑦𝐵𝑦 ∈ (Base‘𝐶)))
6 catidd.h . . . . . . . . . . . . 13 (𝜑𝐻 = (Hom ‘𝐶))
76oveqd 7404 . . . . . . . . . . . 12 (𝜑 → (𝑦𝐻𝑥) = (𝑦(Hom ‘𝐶)𝑥))
87eleq2d 2814 . . . . . . . . . . 11 (𝜑 → (𝑓 ∈ (𝑦𝐻𝑥) ↔ 𝑓 ∈ (𝑦(Hom ‘𝐶)𝑥)))
94, 5, 83anbi123d 1438 . . . . . . . . . 10 (𝜑 → ((𝑥𝐵𝑦𝐵𝑓 ∈ (𝑦𝐻𝑥)) ↔ (𝑥 ∈ (Base‘𝐶) ∧ 𝑦 ∈ (Base‘𝐶) ∧ 𝑓 ∈ (𝑦(Hom ‘𝐶)𝑥))))
10 catidd.o . . . . . . . . . . . . 13 (𝜑· = (comp‘𝐶))
1110oveqd 7404 . . . . . . . . . . . 12 (𝜑 → (⟨𝑦, 𝑥· 𝑥) = (⟨𝑦, 𝑥⟩(comp‘𝐶)𝑥))
1211oveqd 7404 . . . . . . . . . . 11 (𝜑 → ( 1 (⟨𝑦, 𝑥· 𝑥)𝑓) = ( 1 (⟨𝑦, 𝑥⟩(comp‘𝐶)𝑥)𝑓))
1312eqeq1d 2731 . . . . . . . . . 10 (𝜑 → (( 1 (⟨𝑦, 𝑥· 𝑥)𝑓) = 𝑓 ↔ ( 1 (⟨𝑦, 𝑥⟩(comp‘𝐶)𝑥)𝑓) = 𝑓))
142, 9, 133imtr3d 293 . . . . . . . . 9 (𝜑 → ((𝑥 ∈ (Base‘𝐶) ∧ 𝑦 ∈ (Base‘𝐶) ∧ 𝑓 ∈ (𝑦(Hom ‘𝐶)𝑥)) → ( 1 (⟨𝑦, 𝑥⟩(comp‘𝐶)𝑥)𝑓) = 𝑓))
15143expd 1354 . . . . . . . 8 (𝜑 → (𝑥 ∈ (Base‘𝐶) → (𝑦 ∈ (Base‘𝐶) → (𝑓 ∈ (𝑦(Hom ‘𝐶)𝑥) → ( 1 (⟨𝑦, 𝑥⟩(comp‘𝐶)𝑥)𝑓) = 𝑓))))
1615imp41 425 . . . . . . 7 ((((𝜑𝑥 ∈ (Base‘𝐶)) ∧ 𝑦 ∈ (Base‘𝐶)) ∧ 𝑓 ∈ (𝑦(Hom ‘𝐶)𝑥)) → ( 1 (⟨𝑦, 𝑥⟩(comp‘𝐶)𝑥)𝑓) = 𝑓)
1716ralrimiva 3125 . . . . . 6 (((𝜑𝑥 ∈ (Base‘𝐶)) ∧ 𝑦 ∈ (Base‘𝐶)) → ∀𝑓 ∈ (𝑦(Hom ‘𝐶)𝑥)( 1 (⟨𝑦, 𝑥⟩(comp‘𝐶)𝑥)𝑓) = 𝑓)
18 catidd.3 . . . . . . . . . . 11 ((𝜑 ∧ (𝑥𝐵𝑦𝐵𝑓 ∈ (𝑥𝐻𝑦))) → (𝑓(⟨𝑥, 𝑥· 𝑦) 1 ) = 𝑓)
1918ex 412 . . . . . . . . . 10 (𝜑 → ((𝑥𝐵𝑦𝐵𝑓 ∈ (𝑥𝐻𝑦)) → (𝑓(⟨𝑥, 𝑥· 𝑦) 1 ) = 𝑓))
206oveqd 7404 . . . . . . . . . . . 12 (𝜑 → (𝑥𝐻𝑦) = (𝑥(Hom ‘𝐶)𝑦))
2120eleq2d 2814 . . . . . . . . . . 11 (𝜑 → (𝑓 ∈ (𝑥𝐻𝑦) ↔ 𝑓 ∈ (𝑥(Hom ‘𝐶)𝑦)))
224, 5, 213anbi123d 1438 . . . . . . . . . 10 (𝜑 → ((𝑥𝐵𝑦𝐵𝑓 ∈ (𝑥𝐻𝑦)) ↔ (𝑥 ∈ (Base‘𝐶) ∧ 𝑦 ∈ (Base‘𝐶) ∧ 𝑓 ∈ (𝑥(Hom ‘𝐶)𝑦))))
2310oveqd 7404 . . . . . . . . . . . 12 (𝜑 → (⟨𝑥, 𝑥· 𝑦) = (⟨𝑥, 𝑥⟩(comp‘𝐶)𝑦))
2423oveqd 7404 . . . . . . . . . . 11 (𝜑 → (𝑓(⟨𝑥, 𝑥· 𝑦) 1 ) = (𝑓(⟨𝑥, 𝑥⟩(comp‘𝐶)𝑦) 1 ))
2524eqeq1d 2731 . . . . . . . . . 10 (𝜑 → ((𝑓(⟨𝑥, 𝑥· 𝑦) 1 ) = 𝑓 ↔ (𝑓(⟨𝑥, 𝑥⟩(comp‘𝐶)𝑦) 1 ) = 𝑓))
2619, 22, 253imtr3d 293 . . . . . . . . 9 (𝜑 → ((𝑥 ∈ (Base‘𝐶) ∧ 𝑦 ∈ (Base‘𝐶) ∧ 𝑓 ∈ (𝑥(Hom ‘𝐶)𝑦)) → (𝑓(⟨𝑥, 𝑥⟩(comp‘𝐶)𝑦) 1 ) = 𝑓))
27263expd 1354 . . . . . . . 8 (𝜑 → (𝑥 ∈ (Base‘𝐶) → (𝑦 ∈ (Base‘𝐶) → (𝑓 ∈ (𝑥(Hom ‘𝐶)𝑦) → (𝑓(⟨𝑥, 𝑥⟩(comp‘𝐶)𝑦) 1 ) = 𝑓))))
2827imp41 425 . . . . . . 7 ((((𝜑𝑥 ∈ (Base‘𝐶)) ∧ 𝑦 ∈ (Base‘𝐶)) ∧ 𝑓 ∈ (𝑥(Hom ‘𝐶)𝑦)) → (𝑓(⟨𝑥, 𝑥⟩(comp‘𝐶)𝑦) 1 ) = 𝑓)
2928ralrimiva 3125 . . . . . 6 (((𝜑𝑥 ∈ (Base‘𝐶)) ∧ 𝑦 ∈ (Base‘𝐶)) → ∀𝑓 ∈ (𝑥(Hom ‘𝐶)𝑦)(𝑓(⟨𝑥, 𝑥⟩(comp‘𝐶)𝑦) 1 ) = 𝑓)
3017, 29jca 511 . . . . 5 (((𝜑𝑥 ∈ (Base‘𝐶)) ∧ 𝑦 ∈ (Base‘𝐶)) → (∀𝑓 ∈ (𝑦(Hom ‘𝐶)𝑥)( 1 (⟨𝑦, 𝑥⟩(comp‘𝐶)𝑥)𝑓) = 𝑓 ∧ ∀𝑓 ∈ (𝑥(Hom ‘𝐶)𝑦)(𝑓(⟨𝑥, 𝑥⟩(comp‘𝐶)𝑦) 1 ) = 𝑓))
3130ralrimiva 3125 . . . 4 ((𝜑𝑥 ∈ (Base‘𝐶)) → ∀𝑦 ∈ (Base‘𝐶)(∀𝑓 ∈ (𝑦(Hom ‘𝐶)𝑥)( 1 (⟨𝑦, 𝑥⟩(comp‘𝐶)𝑥)𝑓) = 𝑓 ∧ ∀𝑓 ∈ (𝑥(Hom ‘𝐶)𝑦)(𝑓(⟨𝑥, 𝑥⟩(comp‘𝐶)𝑦) 1 ) = 𝑓))
32 catidd.1 . . . . . . . 8 ((𝜑𝑥𝐵) → 1 ∈ (𝑥𝐻𝑥))
3332ex 412 . . . . . . 7 (𝜑 → (𝑥𝐵1 ∈ (𝑥𝐻𝑥)))
346oveqd 7404 . . . . . . . 8 (𝜑 → (𝑥𝐻𝑥) = (𝑥(Hom ‘𝐶)𝑥))
3534eleq2d 2814 . . . . . . 7 (𝜑 → ( 1 ∈ (𝑥𝐻𝑥) ↔ 1 ∈ (𝑥(Hom ‘𝐶)𝑥)))
3633, 4, 353imtr3d 293 . . . . . 6 (𝜑 → (𝑥 ∈ (Base‘𝐶) → 1 ∈ (𝑥(Hom ‘𝐶)𝑥)))
3736imp 406 . . . . 5 ((𝜑𝑥 ∈ (Base‘𝐶)) → 1 ∈ (𝑥(Hom ‘𝐶)𝑥))
38 eqid 2729 . . . . . 6 (Base‘𝐶) = (Base‘𝐶)
39 eqid 2729 . . . . . 6 (Hom ‘𝐶) = (Hom ‘𝐶)
40 eqid 2729 . . . . . 6 (comp‘𝐶) = (comp‘𝐶)
41 catidd.c . . . . . . 7 (𝜑𝐶 ∈ Cat)
4241adantr 480 . . . . . 6 ((𝜑𝑥 ∈ (Base‘𝐶)) → 𝐶 ∈ Cat)
43 simpr 484 . . . . . 6 ((𝜑𝑥 ∈ (Base‘𝐶)) → 𝑥 ∈ (Base‘𝐶))
4438, 39, 40, 42, 43catideu 17636 . . . . 5 ((𝜑𝑥 ∈ (Base‘𝐶)) → ∃!𝑔 ∈ (𝑥(Hom ‘𝐶)𝑥)∀𝑦 ∈ (Base‘𝐶)(∀𝑓 ∈ (𝑦(Hom ‘𝐶)𝑥)(𝑔(⟨𝑦, 𝑥⟩(comp‘𝐶)𝑥)𝑓) = 𝑓 ∧ ∀𝑓 ∈ (𝑥(Hom ‘𝐶)𝑦)(𝑓(⟨𝑥, 𝑥⟩(comp‘𝐶)𝑦)𝑔) = 𝑓))
45 oveq1 7394 . . . . . . . . . 10 (𝑔 = 1 → (𝑔(⟨𝑦, 𝑥⟩(comp‘𝐶)𝑥)𝑓) = ( 1 (⟨𝑦, 𝑥⟩(comp‘𝐶)𝑥)𝑓))
4645eqeq1d 2731 . . . . . . . . 9 (𝑔 = 1 → ((𝑔(⟨𝑦, 𝑥⟩(comp‘𝐶)𝑥)𝑓) = 𝑓 ↔ ( 1 (⟨𝑦, 𝑥⟩(comp‘𝐶)𝑥)𝑓) = 𝑓))
4746ralbidv 3156 . . . . . . . 8 (𝑔 = 1 → (∀𝑓 ∈ (𝑦(Hom ‘𝐶)𝑥)(𝑔(⟨𝑦, 𝑥⟩(comp‘𝐶)𝑥)𝑓) = 𝑓 ↔ ∀𝑓 ∈ (𝑦(Hom ‘𝐶)𝑥)( 1 (⟨𝑦, 𝑥⟩(comp‘𝐶)𝑥)𝑓) = 𝑓))
48 oveq2 7395 . . . . . . . . . 10 (𝑔 = 1 → (𝑓(⟨𝑥, 𝑥⟩(comp‘𝐶)𝑦)𝑔) = (𝑓(⟨𝑥, 𝑥⟩(comp‘𝐶)𝑦) 1 ))
4948eqeq1d 2731 . . . . . . . . 9 (𝑔 = 1 → ((𝑓(⟨𝑥, 𝑥⟩(comp‘𝐶)𝑦)𝑔) = 𝑓 ↔ (𝑓(⟨𝑥, 𝑥⟩(comp‘𝐶)𝑦) 1 ) = 𝑓))
5049ralbidv 3156 . . . . . . . 8 (𝑔 = 1 → (∀𝑓 ∈ (𝑥(Hom ‘𝐶)𝑦)(𝑓(⟨𝑥, 𝑥⟩(comp‘𝐶)𝑦)𝑔) = 𝑓 ↔ ∀𝑓 ∈ (𝑥(Hom ‘𝐶)𝑦)(𝑓(⟨𝑥, 𝑥⟩(comp‘𝐶)𝑦) 1 ) = 𝑓))
5147, 50anbi12d 632 . . . . . . 7 (𝑔 = 1 → ((∀𝑓 ∈ (𝑦(Hom ‘𝐶)𝑥)(𝑔(⟨𝑦, 𝑥⟩(comp‘𝐶)𝑥)𝑓) = 𝑓 ∧ ∀𝑓 ∈ (𝑥(Hom ‘𝐶)𝑦)(𝑓(⟨𝑥, 𝑥⟩(comp‘𝐶)𝑦)𝑔) = 𝑓) ↔ (∀𝑓 ∈ (𝑦(Hom ‘𝐶)𝑥)( 1 (⟨𝑦, 𝑥⟩(comp‘𝐶)𝑥)𝑓) = 𝑓 ∧ ∀𝑓 ∈ (𝑥(Hom ‘𝐶)𝑦)(𝑓(⟨𝑥, 𝑥⟩(comp‘𝐶)𝑦) 1 ) = 𝑓)))
5251ralbidv 3156 . . . . . 6 (𝑔 = 1 → (∀𝑦 ∈ (Base‘𝐶)(∀𝑓 ∈ (𝑦(Hom ‘𝐶)𝑥)(𝑔(⟨𝑦, 𝑥⟩(comp‘𝐶)𝑥)𝑓) = 𝑓 ∧ ∀𝑓 ∈ (𝑥(Hom ‘𝐶)𝑦)(𝑓(⟨𝑥, 𝑥⟩(comp‘𝐶)𝑦)𝑔) = 𝑓) ↔ ∀𝑦 ∈ (Base‘𝐶)(∀𝑓 ∈ (𝑦(Hom ‘𝐶)𝑥)( 1 (⟨𝑦, 𝑥⟩(comp‘𝐶)𝑥)𝑓) = 𝑓 ∧ ∀𝑓 ∈ (𝑥(Hom ‘𝐶)𝑦)(𝑓(⟨𝑥, 𝑥⟩(comp‘𝐶)𝑦) 1 ) = 𝑓)))
5352riota2 7369 . . . . 5 (( 1 ∈ (𝑥(Hom ‘𝐶)𝑥) ∧ ∃!𝑔 ∈ (𝑥(Hom ‘𝐶)𝑥)∀𝑦 ∈ (Base‘𝐶)(∀𝑓 ∈ (𝑦(Hom ‘𝐶)𝑥)(𝑔(⟨𝑦, 𝑥⟩(comp‘𝐶)𝑥)𝑓) = 𝑓 ∧ ∀𝑓 ∈ (𝑥(Hom ‘𝐶)𝑦)(𝑓(⟨𝑥, 𝑥⟩(comp‘𝐶)𝑦)𝑔) = 𝑓)) → (∀𝑦 ∈ (Base‘𝐶)(∀𝑓 ∈ (𝑦(Hom ‘𝐶)𝑥)( 1 (⟨𝑦, 𝑥⟩(comp‘𝐶)𝑥)𝑓) = 𝑓 ∧ ∀𝑓 ∈ (𝑥(Hom ‘𝐶)𝑦)(𝑓(⟨𝑥, 𝑥⟩(comp‘𝐶)𝑦) 1 ) = 𝑓) ↔ (𝑔 ∈ (𝑥(Hom ‘𝐶)𝑥)∀𝑦 ∈ (Base‘𝐶)(∀𝑓 ∈ (𝑦(Hom ‘𝐶)𝑥)(𝑔(⟨𝑦, 𝑥⟩(comp‘𝐶)𝑥)𝑓) = 𝑓 ∧ ∀𝑓 ∈ (𝑥(Hom ‘𝐶)𝑦)(𝑓(⟨𝑥, 𝑥⟩(comp‘𝐶)𝑦)𝑔) = 𝑓)) = 1 ))
5437, 44, 53syl2anc 584 . . . 4 ((𝜑𝑥 ∈ (Base‘𝐶)) → (∀𝑦 ∈ (Base‘𝐶)(∀𝑓 ∈ (𝑦(Hom ‘𝐶)𝑥)( 1 (⟨𝑦, 𝑥⟩(comp‘𝐶)𝑥)𝑓) = 𝑓 ∧ ∀𝑓 ∈ (𝑥(Hom ‘𝐶)𝑦)(𝑓(⟨𝑥, 𝑥⟩(comp‘𝐶)𝑦) 1 ) = 𝑓) ↔ (𝑔 ∈ (𝑥(Hom ‘𝐶)𝑥)∀𝑦 ∈ (Base‘𝐶)(∀𝑓 ∈ (𝑦(Hom ‘𝐶)𝑥)(𝑔(⟨𝑦, 𝑥⟩(comp‘𝐶)𝑥)𝑓) = 𝑓 ∧ ∀𝑓 ∈ (𝑥(Hom ‘𝐶)𝑦)(𝑓(⟨𝑥, 𝑥⟩(comp‘𝐶)𝑦)𝑔) = 𝑓)) = 1 ))
5531, 54mpbid 232 . . 3 ((𝜑𝑥 ∈ (Base‘𝐶)) → (𝑔 ∈ (𝑥(Hom ‘𝐶)𝑥)∀𝑦 ∈ (Base‘𝐶)(∀𝑓 ∈ (𝑦(Hom ‘𝐶)𝑥)(𝑔(⟨𝑦, 𝑥⟩(comp‘𝐶)𝑥)𝑓) = 𝑓 ∧ ∀𝑓 ∈ (𝑥(Hom ‘𝐶)𝑦)(𝑓(⟨𝑥, 𝑥⟩(comp‘𝐶)𝑦)𝑔) = 𝑓)) = 1 )
5655mpteq2dva 5200 . 2 (𝜑 → (𝑥 ∈ (Base‘𝐶) ↦ (𝑔 ∈ (𝑥(Hom ‘𝐶)𝑥)∀𝑦 ∈ (Base‘𝐶)(∀𝑓 ∈ (𝑦(Hom ‘𝐶)𝑥)(𝑔(⟨𝑦, 𝑥⟩(comp‘𝐶)𝑥)𝑓) = 𝑓 ∧ ∀𝑓 ∈ (𝑥(Hom ‘𝐶)𝑦)(𝑓(⟨𝑥, 𝑥⟩(comp‘𝐶)𝑦)𝑔) = 𝑓))) = (𝑥 ∈ (Base‘𝐶) ↦ 1 ))
57 eqid 2729 . . 3 (Id‘𝐶) = (Id‘𝐶)
5838, 39, 40, 41, 57cidfval 17637 . 2 (𝜑 → (Id‘𝐶) = (𝑥 ∈ (Base‘𝐶) ↦ (𝑔 ∈ (𝑥(Hom ‘𝐶)𝑥)∀𝑦 ∈ (Base‘𝐶)(∀𝑓 ∈ (𝑦(Hom ‘𝐶)𝑥)(𝑔(⟨𝑦, 𝑥⟩(comp‘𝐶)𝑥)𝑓) = 𝑓 ∧ ∀𝑓 ∈ (𝑥(Hom ‘𝐶)𝑦)(𝑓(⟨𝑥, 𝑥⟩(comp‘𝐶)𝑦)𝑔) = 𝑓))))
593mpteq1d 5197 . 2 (𝜑 → (𝑥𝐵1 ) = (𝑥 ∈ (Base‘𝐶) ↦ 1 ))
6056, 58, 593eqtr4d 2774 1 (𝜑 → (Id‘𝐶) = (𝑥𝐵1 ))
Colors of variables: wff setvar class
Syntax hints:  wi 4  wb 206  wa 395  w3a 1086   = wceq 1540  wcel 2109  wral 3044  ∃!wreu 3352  cop 4595  cmpt 5188  cfv 6511  crio 7343  (class class class)co 7387  Basecbs 17179  Hom chom 17231  compcco 17232  Catccat 17625  Idccid 17626
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1795  ax-4 1809  ax-5 1910  ax-6 1967  ax-7 2008  ax-8 2111  ax-9 2119  ax-10 2142  ax-11 2158  ax-12 2178  ax-ext 2701  ax-rep 5234  ax-sep 5251  ax-nul 5261  ax-pr 5387
This theorem depends on definitions:  df-bi 207  df-an 396  df-or 848  df-3an 1088  df-tru 1543  df-fal 1553  df-ex 1780  df-nf 1784  df-sb 2066  df-mo 2533  df-eu 2562  df-clab 2708  df-cleq 2721  df-clel 2803  df-nfc 2878  df-ne 2926  df-ral 3045  df-rex 3054  df-rmo 3354  df-reu 3355  df-rab 3406  df-v 3449  df-sbc 3754  df-csb 3863  df-dif 3917  df-un 3919  df-in 3921  df-ss 3931  df-nul 4297  df-if 4489  df-sn 4590  df-pr 4592  df-op 4596  df-uni 4872  df-iun 4957  df-br 5108  df-opab 5170  df-mpt 5189  df-id 5533  df-xp 5644  df-rel 5645  df-cnv 5646  df-co 5647  df-dm 5648  df-rn 5649  df-res 5650  df-ima 5651  df-iota 6464  df-fun 6513  df-fn 6514  df-f 6515  df-f1 6516  df-fo 6517  df-f1o 6518  df-fv 6519  df-riota 7344  df-ov 7390  df-cat 17629  df-cid 17630
This theorem is referenced by:  iscatd2  17642
  Copyright terms: Public domain W3C validator