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Definition df-iedg 26792
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 26790 . 2 class iEdg
2 vg . . 3 setvar 𝑔
3 cvv 3441 . . 3 class V
42cv 1537 . . . . 5 class 𝑔
53, 3cxp 5517 . . . . 5 class (V × V)
64, 5wcel 2111 . . . 4 wff 𝑔 ∈ (V × V)
7 c2nd 7670 . . . . 5 class 2nd
84, 7cfv 6324 . . . 4 class (2nd𝑔)
9 cedgf 26782 . . . . 5 class .ef
104, 9cfv 6324 . . . 4 class (.ef‘𝑔)
116, 8, 10cif 4425 . . 3 class if(𝑔 ∈ (V × V), (2nd𝑔), (.ef‘𝑔))
122, 3, 11cmpt 5110 . 2 class (𝑔 ∈ V ↦ if(𝑔 ∈ (V × V), (2nd𝑔), (.ef‘𝑔)))
131, 12wceq 1538 1 wff iEdg = (𝑔 ∈ V ↦ if(𝑔 ∈ (V × V), (2nd𝑔), (.ef‘𝑔)))
Colors of variables: wff setvar class
This definition is referenced by:  iedgval  26794
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