# Atmost1 constraint

is a global constraint stating that $LaTeX: n$ sets $LaTeX: S_1, \dots, S_n$ of known cardinality should intersect pairwise in at-most one element. If $LaTeX: (s_1, \dots, s_n) \in atmost1(S_1, \dots, S_n, c_1, \cdots, c_n)$ then $LaTeX: s_1\subset S_1, \dots , s_n\subset S_n$, $LaTeX: |s_1|=c_1, \dots, |s_n|=c_n$ and $LaTeX: |s_i\cap s_j| \leq 1$ for all $LaTeX: 1\leq i < j \leq n$.