Certain packing and covering problems associated with the common partial transversals of two families $\mathcal{U}$ and $\mathcal{B}$ of subsets of a set $E$ are ...

Parallel lines are straight lines which have the same direction and so never meet. Arrowheads show lines are parallel. A straight line that cuts a pair of parallel lines is called an intersecting ...

Parallel lines close parallel lines Lines which never meet and stay the same distance apart. Parallel lines are indicated by a pair of arrows. are two or more straight lines that remain the same ...