00291nam a22001217a 450000500170000002000180001710000200003524500420005526000260009730000100012365000180013365000180015120251202105316.0  a9781032687704  aDeBonis, Mark J  aBeginners guide to mathematical proof  aOxonbCRC pressc2025  ax+159  aCombinatorics  aNumber theory