The creasing algorithm templates define four template functions for determining the order properties of sequences, specifically: * Increasing * Decreasing * Strictly Increasing * Strictly Decreasing The implementation is a fairly trivial composition of the STL adjacent_find, not2 and {greater,less,greater_equal,less_equal}. For the purposes of sequence ordering validation, using these templates is more efficient and straightforward than creating a temporary, sorted version of some sequence and comparing it against the original sequence. Example: bool CheckPoints(const Points & inPoints) { const bool strictlyIncreasing = is_strictly_increasing(inPoints.begin(), inPoints.end()); if (!strictlyIncreasing) { cerr << "Points must be in increasing order with " "no duplicate values." << endl; } return strictlyIncreasing; } The review files are available in both Sandbox and Vault: Sandbox: boost/algorithm/creasing.hpp libs/algorithm/creasing/example/creasing_ex.cpp libs/algorithm/creasing/example/Jamfile libs/algorithm/creasing/test/creasing_test.cpp libs/algorithm/creasing/test/Jamfile.v2 Vault: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=creasin g.zip&directory=Algorithms Regards, Grant Erickson