The roots of Domingo de Soto's expression uniform difform motion [uniformly accelerated motion] lies in the Oxford Calculators terms "uniform" motion and "difform" motion. "Uniform" motion was used differently then than it would be now. "Uniform" motion might have referred both to constant speed and to motion in which all parts of a body are moving at equal speed. Apparently, the Calculators did not illustrate the different types of motion with real-world examples. John of Holland at the University of Prague, illustrated uniform motion with what would later be called uniform velocity, but also with a falling stone (all parts moving at the same speed), and with a sphere in uniform rotation. He did, however, make distinctions between different kinds of "uniform" motion. Difform motion was exemplified by walking at increasing speed.