Bernard Bolzano

lived from 1781 to 1848

**Bernard Bolzano** successfully freed calculus from the concept of the infinitesimal. He also gave examples of 1-1 correspondences between the elements of an infinite set and the elements of a proper subset.

*Find out more at*:

http://www-history.mcs.st-andrews.ac.uk/Mathematicians/Bolzano.html