Editing Incidence structure (section)

===Linear spaces===
Incidence structures are seldom studied in their full generality; it is typical to study incidence structures that satisfy some additional axioms. For instance, a ''[[partial linear space]]'' is an incidence structure that satisfies:
# Any two distinct points are incident with at most one common line, and
# Every line is incident with at least two points.
If the first axiom above is replaced by the stronger:
# <li value="3"> Any two distinct points are incident with exactly one common line,</li>
the incidence structure is called a ''[[linear space (geometry)|linear space]]''.<ref>The term ''linear space'' is also used to refer to vector spaces, but this will rarely cause confusion.</ref><ref>{{harvnb|Moorhouse|2014|page=5}}</ref>