In a GEnerate and test algorithm, combining part of the filter with the GEnerator in order to reduce the number of potential solutions GEnerated. A trivial example: filter (< 100) [1..1000] ==> [1..99] where [1..n] GEnerates the list of inteGErs from 1 to n. Here the filter has been combined completely with the GEnerator. This is an example of fusion. (2005-03-18)