A geometric (n4) configuration is a collection of n points and n lines, usually in the Euclidean plane, so that every point lies on four lines and every line passes through four points. This paper introduces a new class of movable ((5m)4) configurations---that is, configurations which admit a continuous family of realizations fixing four points in general position but moving at least one other point---including the smallest known movable (n4) configuration.
@article{17,
title = {A new class of movable (n4) configurations},
journal = {ARS MATHEMATICA CONTEMPORANEA},
volume = {1},
year = {2008},
doi = {10.26493/1855-3974.17.de0},
language = {EN},
url = {http://dml.mathdoc.fr/item/17}
}
Berman, Leah Wrenn. A new class of movable (n4) configurations. ARS MATHEMATICA CONTEMPORANEA, Tome 1 (2008) . doi : 10.26493/1855-3974.17.de0. http://gdmltest.u-ga.fr/item/17/