The heirs of the non-figurative abstract painter Piet mondrian are in legal dispute with the Philadelphia Museum of Art (United States) for Composition with blue, a work valued at 100 million dollars that the Dutch painter completed in 1926 and that has been in the possession of the American institution for 70 years, presumably as a product of Nazi plunder. Composition with blue –A 76.2 x 76.2 x 8.7 cm diamond-shaped painting composed of two black lines and a blue triangle on a white surface– was painted by Piet Mondrian (Amersfoort, Netherlands, 1872 – New York, United States, 1944) during...