Article about specific method of proof ( a diagrammatic method ). Uses triangular numbers as basis for beginning of article. Interactive site. Part of the author´s site "Cut the Knot". Copyright © 1996-2001 Alexander Bogomolny.

Discussion of various aspects of mathematical proof by David C. Royster of the University of North Carolina at Charlotte. Conditional, biconditional, induction proofs and more

Research article by Annie and John Selden at Tennessee Technological University Mathematics Education Resources Co. Article focus is on how proofs are taught: pros and cons; suggestions. Topics include: proof and validation, memory and validation, more.