@article{ANicVVol00, AUTHOR = {Niculitsa, Angela and Voloshin, Vitaly}, TITLE = {About uniquely colorable mixed hypertrees}, JOURNAL = {Discuss. Math. Graph Theory}, FJOURNAL = {Discussiones Mathematicae Graph Theory}, VOLUME = {20}, YEAR = {2000}, NUMBER = {1}, PAGES = {8191}, ISSN = {12343099}, ABSTRACT = {A mixed hypergraph is a triple \HH where $X$ is the vertex set and each of
$\cC$, $\cD$ is a family of subsets of $X$, the $\cC$edges and
$\cD$edges, respectively. A $k$coloring of $\cH$ is a mapping $c: X
\rightarrow [k]$ such that each $\cC$edge has two vertices with the same
color and each $\cD$edge has two vertices with distinct colors. \HH is
called a mixed hypertree if there exists a tree $T=(X,\cE)$ such that every
$\cD$edge and every $\cC$edge induces a subtree of $T.$ A mixed
hypergraph $\cH$ is called uniquely colorable if it has precisely one
coloring apart from permutations of colors. We give the characterization of
uniquely colorable mixed hypertrees.
}, }
