%query: select(i,o,o). %% select(X, Xs, Zs) :- Zs is the result of deleting one occurrence of X %% from the list Xs. %TWTYPES :- type select(poly,list,list). select(X, [X | Xs], Xs). select(X, [Y | Xs], [Y | Zs]) :- select(X, Xs, Zs). /*TWDESC select(X, Xs, Zs) :- Zs is the result of deleting one occurrence of X from the list Xs. */ /*TWTYPES list([]). list([X|Xs]) :- poly(X), list(Xs). poly(dummy). */ /*TWDEMO selected_norms([list,poly]). query(select(f,f,b,f,f,f)). query(select(f,f,f,b,f,f)). query(select(f,f,f,f,b,f)). query(select(f,f,f,f,f,b)). */