../code/conceptPage.scroll id shared-prolog name Shared Prolog appeared 1990 tags pl lab Universitci di Pisa && Universitci di Udine country Italy reference https://semanticscholar.org/paper/0e2bd2386d4b9a2ec012c40359884c83793acfe5 hopl https://hopl.info/showlanguage.prx?exp=6621