  Clique-width is a well-known graph parameter. Many NP-hard graph problems
admit polynomial-time solutions when restricted to graphs of bounded
clique-width. The same holds for NLC-width. In this paper we study the behavior
of clique-width and NLC-width under various graph operations and graph
transformations. We give upper and lower bounds for the clique-width and
NLC-width of the modified graphs in terms of the clique-width and NLC-width of
the involved graphs.
