The treewidth, pathwidth, and treedepth of a pattern are those of its underlying simple graph, so edge multiplicities play no role. A pattern has treewidth at most $k$ if it has a tree decomposition whose bags have at most $k + 1$ vertices, and pathwidth at most $k$ if it has such a decomposition whose tree is a path. It has treedepth at most $t$ if it has an elimination forest in which every root-leaf path has at most $t$ vertices. The pattern without vertices has treewidth, pathwidth, and treedepth zero.