Tagless, Data Types a la Carte, or manually. I'm currently leaning toward DTalaC, but not strongly. There seem to be two packages which implement the DTalaC style: syntactic and compdata. Alternatively, I can write the common code myself. Does anyone have recommendations for which one to use, and any materials for learning to use them? --=20 =C2=A0=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0Alex R