 Euler rejected the concept of infinitesimal in its sense as a quantity less than any assignable magnitude and yet unequal to 0, arguing: that differentials must be zeros, and \(\Dy/\Dx\) the quotient \(0/0\). Since for any number \(\alpha\), \(\alpha \cdot 0 = 0\), Euler maintained that the quotient \(0/0\) could represent any number  whatsoever.[23]  For Euler qua formalist the calculus was essentially a procedure for determining the value of the expression \(0/0\) in the manifold situations it arises as the ratio of evanescent increments.