Procedure to intersects two lists, returning a list containing three lists: The first list returned is everything in lista that wasn't in listb. The second list contains the intersection of the two lists, and the third list contains all the elements that were in listb but weren't in lista. The returned lists will be sorted.
Usage:
intersect3 lista listb
Example:
package require Tclx
intersect3 {a b c d e} {d e d f g c} ;# ==> {a b} {c d e} {f g}Category Command, part of Tclx