On Thu, Nov 4, 2010 at 4:32 PM, Jason Grout <jason-s...@creativetrax.com> wrote: > On 11/4/10 6:12 PM, rjf wrote: >> >> 1. can you prove a program correct without looking at its source code? >> answer: yes, sometimes. > > I'm really curious. How would you do prove a program correct without > looking at its source code? (I assume "prove correct" means that you > guarantee that a certain set of inputs gives a corresponding certain set of > outputs, assuming a perfect computer, compiler, no cosmic rays, etc.)
Here's a trivial example. Suppose you have a program that is (1) deterministic, and (2) has only finitely many inputs. Then you could prove it correct by trying all of the inputs :-) Proofs are *tools* that one uses in daily work when doing mathematical research that dramatically increase depth of understanding, and guide one on the right path. It is difficult for spectators who don't do actual mathematics to understand this; some of them end up making bizarre comments about tin cups. -- William -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
