What do the integers have in common with the symmetries of a triangle? In the 19th century, mathematicians invented groups as an answer to this question. Mathematics started with numbers — clear, ...

This is a preview. Log in through your library . Abstract The work described in this article was based on a historical perspective in order to analyze the extension of the natural-number domain to the ...

PNAS is the world's most-cited multidisciplinary scientific serial. It publishes high-impact research reports, commentaries, perspectives, reviews, colloquium papers, and actions of the Academy. In ...