This page does not represent the most current semester of this course; it is present merely as an archive.

You have enough to worry about memorizing without keeping all these terms in your head. We intend to provide this list for your reference during every in-class evaluation relating to graphs.

Term Definition
Walk

An alternating sequence of vertices and edges

• starting and ending with a vertex,
• each edge (x,y) in the walk follows vertex x and is followed by vertex y
Path A walk that does not visit any vertex twice
Closed Walk A walk that begins and ends at the same vertex
Cycle A closed walk that is a path except for its last vertex

The related definitions on relations R : A \rightarrow A are

Term Definition
R is Reflexive \forall x \in A \;.\; x R x
R is Irreflexive \forall x \in A \;.\; \lnot(x R x)
R is Symmetric \forall x,y \in A \;.\; (x R y) \rightarrow (y R x)
R is Asymmetric \forall x,y \in A \;.\; (x R y) \rightarrow \lnot(y R x)
R is Antisymmetric \forall x \neq y \in A \;.\; (x R y) \rightarrow \lnot(y R x)
R is Transitive \forall x,y,z \in A \;.\; (x R y) \land (y R z) \rightarrow (x R z)

And those lead to these terms:

Term Definition
Strict partial order transitive and asymmetric
Weak partial order transitive, reflexive, and antisymmetric
Equivalence relation transitive, reflexive, and symmetric