Algorithms: bisection routine

Contributions to this (leparlmeni musl be in lhe form stated in the Algorithms /)el)art, me~:t Policy Statemm:){ (Communications, Febru'~ry, 1960). (?(mtribuiions should be seut to J. H. Wegsteilt, C, omputation Lal)orator3". National Bureau of Sta~d'trds, Washinglon 25, l). C. Algorithms should I)e in the Publication fOrln of AI,tI()L and written in a. style patterned M'ter the most recent algorithms appearing in lifts det:)artlnen~. Although each algorithm has been lested by its contributor, no warr:mty, express ()r implied, is made bs" the contributor, the edilor, or the Association for Computing Machinery as 1o (he ac(:urac3 and fmwtioning of the algorithm and rel'tted ~dgorithm material, and no re:sponsibilil y is assmned by tim contributor, the editor, (,r lhe Assoeiatiort for Computing Machinery in e(mneelion therewith. The reproduction of algorilhlnS appearing in lhis del)arlment is explicitly permitted wilhout any charge. When reproduelion is for publication lmrposes, reference must t)e made to the algorithm autJmr a~d to the Communications issue bearing the algorithm.