Editing Incidence structure (section)

===Hypergraphs===
{{main|Hypergraph}}
[[File:Fano plane with nimber labels.svg|thumb|right|Seven points are elements of seven lines in the [[Fano plane]]]]
Each [[hypergraph]] or [[set system]] can be regarded as an incidence
structure in which the [[universal set]] plays the role of "points", the corresponding [[family of subsets]] plays the role of "lines" and the incidence relation is [[Element (mathematics)|set membership]] "{{math|∈}}".  Conversely, every incidence structure can be viewed as a hypergraph by identifying the lines with the sets of points that are incident with them.