Relative precision in the inductive assertion method
The inductive assertion method of Floyd is here applied to programs involving floating point numbers, using a new verification condition generator for C programs known as ProveIt. The exit assertions of such programs need to state that the answers are correct to within some tolerance. We define this notion of tolerance, and show that it is equivalent to Olver's notion of relative precision. As an example, we present an O(ln n) program which takes the nth power of a, and show that the speed of the program does not improve the relative precision, which remains 2n rather than the expected 2 ln n.
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