Jean-Pierre Vasarely (1934–2002), professionally known as Yvaral, was a French artist working in the fields of op-art and kinetic art from 1954 onwards. He was the son of Victor Vasarely. Yvaral studied graphic art and publicity at the Ecole des Arts Appliques between 1950 and 1953. In 1960, Yvaral co-founded the Groupe de Recherche d'Art Visuel (GRAV) with Julio Le Parc, François Morellet, Francisco Sobrino, Horacio Garcia Rossi and Joel Stein, seeking to develop a coherent abstract visual language composed of simple geometric elements. In 1975 he coined the phrase 'Numerical Art' to describe artwork composed (or programmed) according to numerical rules or algorithms.