TY - BOOK

T1 - An Infinite Sequence of Full AFL-Structures, Each of Which Possesses an Infinite Hierarchy

AU - Asveld, Peter R.J.

PY - 1999

Y1 - 1999

N2 - We investigate different sets of operations on languages which result in corresponding algebraic structures, viz. in different types of full AFL’s (full Abstract Family of Languages). By iterating control on ETOL-systems we show that there exists an infinite sequence Cm(m⩾1) of classes of such algebraic structures (full AFL-structures): each class is a proper superset of the next class (Cm ⊃ Cm +1). In turn each class Cm contains a countably infinite hierarchy, i.e. a countably infinite chain of language families Km,n (n⩾1) such that (i) each Km,n is closed under the operations that determine C m and (ii) each K m,n is properly included in the next one: Km,n ⊂ Km,n+1.

AB - We investigate different sets of operations on languages which result in corresponding algebraic structures, viz. in different types of full AFL’s (full Abstract Family of Languages). By iterating control on ETOL-systems we show that there exists an infinite sequence Cm(m⩾1) of classes of such algebraic structures (full AFL-structures): each class is a proper superset of the next class (Cm ⊃ Cm +1). In turn each class Cm contains a countably infinite hierarchy, i.e. a countably infinite chain of language families Km,n (n⩾1) such that (i) each Km,n is closed under the operations that determine C m and (ii) each K m,n is properly included in the next one: Km,n ⊂ Km,n+1.

KW - HMI-SLT: Speech and Language Technology

M3 - Report

T3 - CTIT Technical Report Series

BT - An Infinite Sequence of Full AFL-Structures, Each of Which Possesses an Infinite Hierarchy

PB - Centre for Telematics and Information Technology (CTIT)

CY - Enschede

ER -