05c9905c2505c3505c8005c8205c8590b15 abstract algebra butinthissection combinatorialoptimization combinatorialprobabilities combinatorics complexnetworks extremalproblems fields graphalgorithms graphicmethods graphsandabstractalgebra(groups graphtheory logic mathematicalprogramming networkmodels noneoftheabove operationsresearch operationsresearchandmanagementscience patternperception patternrecognitionsystems rings smallworldgraphs socialsciences statisticalmethods stochastic symbolicandmathematical