▁were ▁Thomas ▁Ott mann , ▁Wolfgang ▁J ank o ▁and ▁ ▁Jan ▁van ▁Lee uw en ▁( U tre cht ). ▁ ▁In ▁ 1 9 8 4 ▁he ▁was ▁appointed ▁professor ▁at ▁the ▁Hoch schule ▁Ful da ▁( F ul da ▁University ▁of ▁App lied ▁Sciences ) ▁and ▁ ▁went ▁from ▁there ▁in ▁ 1 9 8 7 ▁to ▁the ▁University ▁of ▁K ass el ▁where ▁he ▁served ▁as ▁full ▁professor ▁and ▁chairman ▁of ▁ ▁the ▁database ▁group ▁since ▁ 1 9 8 9 ▁until ▁his ▁ret irement ▁in ▁March ▁ 2 0 1 5 . ▁L utz ▁Weg ner ▁is ▁divor ced ▁and ▁has ▁three ▁children . ▁ ▁Ach iev ements ▁ ▁L utz ▁Weg ner ▁started ▁his ▁career ▁with ▁fundamental ▁research ▁on ▁two - level ▁gr amm ars , ▁also ▁known ▁as ▁ ▁van ▁W ij ng a arden ▁gr amm ars ▁which ▁had ▁been ▁used ▁to ▁define ▁the ▁programming ▁language ▁Alg ol 6 8 . ▁His ▁results ▁were ▁included ▁in ▁the ▁Hand book ▁of ▁F ormal ▁L anguages ▁by ▁Ar to ▁Sal oma a ▁and ▁Gr zeg or z ▁Ro zen berg . ▁For ▁his ▁second ▁th esis ▁he ▁developed ▁variants ▁of ▁Quick sort ▁suitable ▁for ▁mult is et ▁and ▁proved ▁that ▁they ▁ ▁achieved ▁the ▁lower ▁bound ▁for ▁quick sort ▁algorithms ▁previously ▁given ▁by ▁Robert ▁S edge wick . ▁ ▁Following ▁a ▁s abb at ical ▁stay ▁at ▁the ▁IBM ▁Scient ific ▁Center ▁Heidel berg ▁he ▁took ▁an ▁interest ▁in ▁the ▁Non - First ▁Normal - Form ▁data