Foundations of geometry different sets of axioms for Euclidean geometry, any of these can replace the Euclidean parallel postulate. The following partial list indicates some of these theorems that are of historical interest. Absolute geometry is a geometry based on an axiom system consisting of all the axioms giving Euclidean geometry except for the parallel postulate or any of its alternatives. The term was introduced by János Bolyai in 1832. It is sometimes referred to as neutral geometry, as it is neutral with respect to the parallel postulate. In Euclid's "Elements", the first 28 propositions and Proposition I.31 avoid using the parallel postulate,
Elements of Algebra Elements of Algebra Elements of Algebra is an elementary mathematics textbook written by mathematician Leonhard Euler and originally published in 1770 in German. "Elements of Algebra" is one of the earliest books to set out algebra in the modern form we would recognize today (another early book being "Elements of Algebra" by Nicholas Saunderson, published in 1740), and is one of Euler's few writings, along with "Letters to a German Princess", that are accessible to the general public. Written in numbered paragraphs as was common practice till the 19th century, "Elements" begins with the definition of mathematics and builds on