Later, write-up-Marxist and anarchist tendencies grew to become sizeable soon after affect from the Situationists, the failure of Italian significantly-still left movements in the seventies and the emergence of a amount of essential theorists which includes Antonio Negri, who experienced contributed to the 1969 founding of Potere Operaio as effectively as Mario Tronti, Paolo Virno and Franco "Bifo" Berardi.