2007-05-31 ago simplified/unified list fold;
2007-03-30 ago simplified constant representation in code generator
2007-01-09 ago improved names
2006-10-04 ago cleaned up some mess
2006-10-02 ago various code refinements
2006-09-19 ago (void)
2006-07-12 ago adaptions in codegen
2006-06-06 ago added type inference at the end of normalization
2006-03-07 ago substantial improvement in codegen iml
2006-03-03 ago improvements for nbe
2006-03-01 ago refined representation of codegen intermediate language
2006-02-27 ago added nbe, updated neb_*
2006-02-21 ago New normalization-by-evaluation package