ldl> Also, I find something more along the lines of an Earley ldl> algorithm quite interesting (recently found the Accent Compiler ldl> Compiler), so am looking at how that all works, in general. John Aycock's SPARK toolkit uses an Earley algorithm: http://www.csr.UVic.CA/~aycock/python/ -- Skip Montanaro (skip@mojam.com) http://www.mojam.com/ http://www.musi-cal.com/