A manuscript, kept in the Library of the University of Bologna, contains data regarding the sign of equality (=). These data have been communicated to me by Professor E. Bortolotti and tend to show that (=) as a sign of equality was developed at Bologna independently of Robert Recorde and perhaps earlier.

We now know that Harriot was not directly responsible for the Praxis, which was put together after his death from papers which are no longer extant by Walter Warner (and, perhaps, one or two others), when Nathaniel Torporley had failed to complete the task which had been assigned to him in Harriot's will. Torporley was a respected mathematician of the day, reputed to have been associated with Viéte himself. The manuscripts that we do have (in the British Library and Petworth) cannot have been the origin of the Praxis, not only on account of their disorder and incoherence, but also because there are significant differences between them and the published work. Notably, the inequality signs associated with his name are never found in his handwriting in the manuscripts but appear throughout as and . Similarity, equality is denoted in the manuscripts by II and not by = (the sign introduced by Robert Recorde), as in the Praxis. The significance of the inequality signs lies in the fact that this is the first time that such signs were used and accorded the same status as the equality sign.