%% file: proglang2.pro %% line: some knowledge about programming languages % language(L) means L is a programming language language(smalltalk). language(lisp). language(prolog). language(snobol). language(apl). % essence(L,DT,CF) means language L features datatype DT % and computational formalism CF essence(smalltalk, objects, 'message passing'). essence(lisp, lists, 'recursive functions'). essence(prolog, relations, 'logical inferencing'). essence(snobol, pattern, 'string processing'). essence(apl, matrix, 'matrix operations'). % history(L,I,D) means language L was invented by I in year D history(smalltalk, inventor('Alan Kay'), date(1980)). history(lisp, inventor('John McCarthy'), date(1959)). history(prolog, inventor('Alan Colmeraur'), date(1971)). history(snobol, inventor('Ralph Griswold'), date(1962)). history(apl, inventor('Kenneth Iverson'), date(1964)).