H. Jerome Keisler has made freely available his calculus textbook, Elementary Calculus: An Approach Using Infinitesimals. The book is based on Abraham Robinson’s rigorous foundations for infinitesimals.

H. Jerome Keisler has made freely available his calculus textbook, Elementary Calculus: An Approach Using Infinitesimals. The book is based on Abraham Robinson’s rigorous foundations for infinitesimals.