This package provides functions which are useful while dealing with set partitions. We provide (hopefully) fast methods for sets of size up to 15 and methods with no set size restrictions which use BigInteger objects. The later ones are constrained only by the available memory size and the expected life length of the user.
The package is named after Eric Temple Bell (1883 - 1960), see Bell, E. T. "Exponential Numbers", Amer. Math. Monthly 41, 411-419, 1934. For more information on set partitions see Weisstein, Eric W. "Set Partition", From MathWorld - A Wolfram Web Resource. Bell package is used in an implementation of VE for IN #CSP.
For a detailed description see JavaDocs [HTML] [PDF 29kB]. The package is made available under GNU General Public License.
Package: JAR file with source code + JavaDocs [ZIP 104kB]
Applet shown below, given a nonnegative integer 'n' computes the number of partitions of the set of size 'n' (the 'n'-th Bell number):