// facts from an art database
painting("Bathers at Asnires", seurat, 1884);
painting("Sunday Afternoon", seurat, 1886);
painting("The Models", seurat, 1888);
//...
artist(cezanne, paul, 1839);
artist(gauguin, paul, 1848);
artist(seurat, georges, 1859);
//...

painterAge(Artist, Title, Age) :-
    artist(Artist, First, Born),
    painting(Title, Artist, Year),
    #(Age, Year - Born);