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Definition df-gid 26732
 Description: Define a function that maps a group operation to the group's identity element. (Contributed by FL, 5-Feb-2010.) (Revised by Mario Carneiro, 15-Dec-2013.) (New usage is discouraged.)
Assertion
Ref Expression
df-gid GId = (𝑔 ∈ V ↦ (𝑢 ∈ ran 𝑔𝑥 ∈ ran 𝑔((𝑢𝑔𝑥) = 𝑥 ∧ (𝑥𝑔𝑢) = 𝑥)))
Distinct variable group:   𝑢,𝑔,𝑥

Detailed syntax breakdown of Definition df-gid
StepHypRef Expression
1 cgi 26728 . 2 class GId
2 vg . . 3 setvar 𝑔
3 cvv 3173 . . 3 class V
4 vu . . . . . . . . 9 setvar 𝑢
54cv 1474 . . . . . . . 8 class 𝑢
6 vx . . . . . . . . 9 setvar 𝑥
76cv 1474 . . . . . . . 8 class 𝑥
82cv 1474 . . . . . . . 8 class 𝑔
95, 7, 8co 6549 . . . . . . 7 class (𝑢𝑔𝑥)
109, 7wceq 1475 . . . . . 6 wff (𝑢𝑔𝑥) = 𝑥
117, 5, 8co 6549 . . . . . . 7 class (𝑥𝑔𝑢)
1211, 7wceq 1475 . . . . . 6 wff (𝑥𝑔𝑢) = 𝑥
1310, 12wa 383 . . . . 5 wff ((𝑢𝑔𝑥) = 𝑥 ∧ (𝑥𝑔𝑢) = 𝑥)
148crn 5039 . . . . 5 class ran 𝑔
1513, 6, 14wral 2896 . . . 4 wff 𝑥 ∈ ran 𝑔((𝑢𝑔𝑥) = 𝑥 ∧ (𝑥𝑔𝑢) = 𝑥)
1615, 4, 14crio 6510 . . 3 class (𝑢 ∈ ran 𝑔𝑥 ∈ ran 𝑔((𝑢𝑔𝑥) = 𝑥 ∧ (𝑥𝑔𝑢) = 𝑥))
172, 3, 16cmpt 4643 . 2 class (𝑔 ∈ V ↦ (𝑢 ∈ ran 𝑔𝑥 ∈ ran 𝑔((𝑢𝑔𝑥) = 𝑥 ∧ (𝑥𝑔𝑢) = 𝑥)))
181, 17wceq 1475 1 wff GId = (𝑔 ∈ V ↦ (𝑢 ∈ ran 𝑔𝑥 ∈ ran 𝑔((𝑢𝑔𝑥) = 𝑥 ∧ (𝑥𝑔𝑢) = 𝑥)))
 Colors of variables: wff setvar class This definition is referenced by:  gidval  26750
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