UndirectedEdge

An undirected edge between two vertices — the edge head Graph holds in its edge list.

✓ checked against that system · ! checked, with disagreements (hover a chip)Wolfram LanguageUndirectedEdge✓↗

UndirectedEdge(u, v)an edge between $u$ and $v$, undirected — VertexDegree and the connectivity heads count it toward both endpoints and traverse it in either direction, regardless of which argument is which.

Typed signatures

Type	Package	Applies
(any, any) -> value	combinatorics	always

Domain: Collections

Details

• Inert, like Graph itself — it holds exactly as written; nothing here evaluates it away.
• Wolfram prints this infix as $u \leftrightarrow v$ (u <-> v); Epsil has no infix form for it yet, so it round-trips through call-form syntax, UndirectedEdge(u, v), which Wolfram accepts as equivalent input.

Examples

Basic #

An edge between 1 and 2

live ↗

In$\mathrm{UndirectedEdge}(1, 2)$Out$\mathrm{UndirectedEdge}(1, 2)$

Scope #

live ↗

In$\mathrm{Subgraph}(\mathrm{CompleteGraph}(4), \bigl\lbrack\mathrm{UndirectedEdge}(1, 2), \mathrm{UndirectedEdge}(2, 3)\bigr\rbrack)$Out$\mathrm{Graph}(\bigl\lbrack1, 2, 3\bigr\rbrack, \bigl\lbrack\mathrm{UndirectedEdge}(1, 2), \mathrm{UndirectedEdge}(1, 3), \mathrm{UndirectedEdge}(2, 3)\bigr\rbrack)$

About

Examples	2
Checked against	Wolfram Language 2 agree
Crosswalk	Wolfram Language

See also: DirectedEdge, Graph