SISNAN(3) LAPACK routine of NEC Numeric Library Collection SISNAN(3) NAME SISNAN SYNOPSIS LOGICAL FUNCTION SISNAN (SIN) PURPOSE SISNAN returns .TRUE. if its argument is NaN, and .FALSE. otherwise. To be replaced by the Fortran 2003 intrinsic in the future. ARGUMENTS SIN (input) SIN is REAL Input to test for NaN. LAPACK routine 31 October 2017 SISNAN(3)