# Sums of Two and Four Squares

 Title: Sums of Two and Four Squares Author: Roelof Oosterhuis Submission date: 2007-08-12 Abstract: This document presents the mechanised proofs of the following results:any prime number of the form 4m+1 can be written as the sum of two squares;any natural number can be written as the sum of four squares BibTeX: @article{SumSquares-AFP, author = {Roelof Oosterhuis}, title = {Sums of Two and Four Squares}, journal = {Archive of Formal Proofs}, month = aug, year = 2007, note = {\url{https://isa-afp.org/entries/SumSquares.html}, Formal proof development}, ISSN = {2150-914x}, } License: BSD License Status: [ok] This is a development version of this entry. It might change over time and is not stable. Please refer to release versions for citations.