Complex sentence: For example, in the traveling salesman problem each state is typically defined as a permutation of the cities to be visited, and its neighbours are the set of permutations produced by reversing the order of any two successive cities.
Split into simpler sentences: For example, in the traveling salesman problem each state is typically defined as a permutation of the cities to be visited. The neighbours of a state are the set of permutations that are produced, for example, by reversing the order of any two successive cities.