| <!-- return types: from API spec., p. 89, 6.13.6 Relational Functions; | |
| and OpenCL C spec., p. 20, 9.4.5 Half - Relational Functions. | |
| These words apply to: isequal, isgreater, isgreaterequal, isless, | |
| islessequal, and islessgreater. --> | |
| <para> | |
| The function returns 0 if either argument is not a number (NaN). | |
| </para> | |
| <!-- 13-Dec-2013, rev. 19 --> | |