This UGen tests for infinity, NaN (not a number), and denormals. If one of these is found, it posts a warning. Its output is as follows: 0 = a normal float, 1 = NaN, 2 = infinity, and 3 = a denormal.
| in | the UGen whose output is to be tested. | 
| id | an id number to identify this UGen. The default is 0. | 
| post | One of three post modes: 
 The default post mode is 2. Post mode 1 is retained for backward compatibility; be aware that it generates a large amount of output. |