When a function is expecting a <number> argument, the following baseline rules will apply unless the function documents different behavior:
 * A missing argument causes the function to fail and return the empty string.  The function will not have performed any action. 
 * Integer arguments are converted using strtoimax(3). 
 * Float arguments are converted using atof(3). 
 * Integer return values are generated with ltoa() [which is builtin to the client]. 
 * Float return values are generated with “%.50g” 
 * “nan” is usually returned if a floating point operationg resulted in an NaN. 
 * “DOM” is returned if a floating point operation resulted in an EDOM error 
 * “RANGE” is returned if a floating point operation resulted in an ERANGE error