../code/conceptPage.scroll id isabelle-hol name Isabelle/HOL appeared 1997 tags pl lab University of Queensland && Technische Universit at Berlin country Australia and Germany reference https://semanticscholar.org/paper/0143b4c8e07bc855683a2ec9ba30895a3eb13208 hopl https://hopl.info/showlanguage.prx?exp=3690