../code/conceptPage.scroll id phocus name PHOCUS appeared 1987 tags pl description An object-oriented Prolog-like language. lab Experimental and Clinical Research Center country Germany reference https://semanticscholar.org/paper/5ad3456657e84641d8539fb31ff9d4ecab1176c3 hopl https://hopl.info/showlanguage.prx?exp=1350