RR-92-30-axiom.dvi

Various feature descriptions are being employed in logic program ming languages and constrained based grammar formalisms The com mon notational primitive of these descriptions are functional attributes called features The descriptions considered in this paper are the possi bly quanti ed rst order formulae obtained from a signature of binary and unary predicates called features and sorts respectively We estab lish a rst order theory FT by means of three axiom schemes show its completeness and construct three elementarily equivalent models One of the models consists of so called feature graphs a data struc ture common in computational linguistics The other two models con sist of so called feature trees a record like data structure generalizing the trees corresponding to rst order terms Our completeness proof exhibits a terminating simpli cation sys tem deciding validity and satis ability of possibly quanti ed feature descriptions