printf "%.20g\n", 123456789123456789;
# produces 123456789123456784
-Testing for exact equality of floating-point equality or inequality is
-not a good idea. Here's a (relatively expensive) work-around to compare
+Testing for exact floating-point equality or inequality is not a
+good idea. Here's a (relatively expensive) work-around to compare
whether two floating-point numbers are equal to a particular number of
decimal places. See Knuth, volume II, for a more robust treatment of
this topic.