and even if we filter nans out 1/x will raise the
divbyzero flag.
<p>
-When a library wants to raise a flag deliberatly
+When a library wants to raise a flag deliberately
but feraiseexcept is not available for some reason,
-then simple arithmetics can be be used just for its
+then simple arithmetics can be be used just for their
exception raising side effect
(eg. 1/0.0 to raise divbyzero), however beaware
of compiler optimizations (dead code elimination,..).