## Related pagesIsomorphisms of linear spacesSmall linear spaces Block plans |

- Each two distinct points are on a unique common line.
- Each line has at least two points.

If is a finite linear space, we denote the number of points and lines of by v and b, respectively. Using this notation, the following important theorem holds.

**Theorem.**
and b=v if and only if
is an, eventually degenerated, projective plane.

In fact, all linear spaces with b not too far distant from v are known, in some sense. These are the so called restricted linear spaces.

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