Editing Combinatorics (section)

===Matroid theory===
{{Main|Matroid theory}}
Matroid theory abstracts part of [[geometry]]. It studies the properties of sets (usually, finite sets) of vectors in a [[vector space]] that do not depend on the particular coefficients in a [[linear independence|linear dependence]] relation.  Not only the structure but also enumerative properties belong to matroid theory.  Matroid theory was introduced by [[Hassler Whitney]] and studied as a part of order theory.  It is now an independent field of study with a number of connections with other parts of combinatorics.