The collection also includes important paintings by Rubens, Frans Hals, Veronese, Konrad Witz, and Martin Schongauer.
There is no artwork made by Konrad Witz included in the collection. 
mnli hypothesis: There is no artwork made by Konrad Witz included in the collection.  premise: The collection also includes important paintings by Rubens, Frans Hals, Veronese, Konrad Witz, and Martin Schongauer.