Edsger Wybe Dijkstra: The nature of my research and why I do it. EWD, 1986. november 14. [2012. július 15-i dátummal az eredetiből archiválva]. (Hozzáférés: 2010. július 3.) „But also 0 is certainly finite and by defining the product of 0 factors —how else?— to be equal to 1 we can do away with the exception: "If n is a positive integer, then n is a finite product of primes."”
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Edsger Wybe Dijkstra: How Computing Science created a new mathematical style. EWD, 1990. március 4. (Hozzáférés: 2010. január 20.) „Hardy and Wright: “Every positive integer, except 1, is a product of primes”, Harold M. Stark: “If n is an integer greater than 1, then either n is prime or n is a finite product of primes.”. These examples —which I owe to A.J.M. van Gasteren— both reject the empty product, the last one also rejects the product with a single factor.”
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Edsger Wybe Dijkstra: The nature of my research and why I do it. EWD, 1986. november 14. [2012. július 15-i dátummal az eredetiből archiválva]. (Hozzáférés: 2010. július 3.) „But also 0 is certainly finite and by defining the product of 0 factors —how else?— to be equal to 1 we can do away with the exception: "If n is a positive integer, then n is a finite product of primes."”
