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Definition df-iedg 29034
Description: Define the function mapping a graph to its indexed edges. This definition is very general: It defines the indexed edges for any ordered pair as its second component, and for any other class as its "edge function". It is meaningful, however, only if the ordered pair represents a graph resp. the class is an extensible structure (containing a slot for "edge functions") representing a graph. (Contributed by AV, 20-Sep-2020.)
Assertion
Ref Expression
df-iedg iEdg = (𝑔 ∈ V ↦ if(𝑔 ∈ (V × V), (2nd𝑔), (.ef‘𝑔)))

Detailed syntax breakdown of Definition df-iedg
StepHypRef Expression
1 ciedg 29032 . 2 class iEdg
2 vg . . 3 setvar 𝑔
3 cvv 3488 . . 3 class V
42cv 1536 . . . . 5 class 𝑔
53, 3cxp 5698 . . . . 5 class (V × V)
64, 5wcel 2108 . . . 4 wff 𝑔 ∈ (V × V)
7 c2nd 8029 . . . . 5 class 2nd
84, 7cfv 6573 . . . 4 class (2nd𝑔)
9 cedgf 29021 . . . . 5 class .ef
104, 9cfv 6573 . . . 4 class (.ef‘𝑔)
116, 8, 10cif 4548 . . 3 class if(𝑔 ∈ (V × V), (2nd𝑔), (.ef‘𝑔))
122, 3, 11cmpt 5249 . 2 class (𝑔 ∈ V ↦ if(𝑔 ∈ (V × V), (2nd𝑔), (.ef‘𝑔)))
131, 12wceq 1537 1 wff iEdg = (𝑔 ∈ V ↦ if(𝑔 ∈ (V × V), (2nd𝑔), (.ef‘𝑔)))
Colors of variables: wff setvar class
This definition is referenced by:  iedgval  29036
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