"Important for containing the evidence, as embodied in the correspondence between Leibnitz and Jean Bernoulli, on the question of the rival claims to superiority in the invention of the calculus between Newton and Leibnitz," states Babson. "It was the only serious claim published in Leibnitz's favour and a tardy answer to the Commercium Epistolicum, which gave the evidence in Newton's favour." Nevertheless, as Babson adds, Leibnitz's notation was undoubtedly superior to Newton's fluxional one.