... goal(farg(synsem,X,SynVal),farg(loc,SynVal,LocVal),farg(cat,LocVal,CatVal),farg(head,CatVal,HdVal),whentype(verb,HdVal,(farg(marking,CatVal,MkVal),whentype(fin,MkVal,(X=synsem:loc:cat:head:vform:bse))))).(6) ... Modularity: the cost in claritySemantic types and inheritance serve to organizethe constraints and overall structure of an HPSGgrammar. This is certainly a familiar, albeit vaguejustification ... when/2,are: (1) suspending until a variable is instantiated, and (2) suspending until two variables are equatedor inequated. The latter corresponds exactly tostructure-sharing in TFSs, and to shared...