Transversal (combinatorics)
A LINE THAT INTERSECTS A SYSTEM OF LINES.
System of distinct representatives; Transversal (group theory); Hypergraph transversal
In mathematics, particularly in combinatorics, given a family of sets, here called a collection C, a transversal (also called a cross-section) is a set containing exactly one element from each member of the collection. When the sets of the collection are mutually disjoint, each element of the transversal corresponds to exactly one member of C (the set it is a member of).