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dlaisnan examples
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Man Page Details
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 Online html documentation available at 
            http://www.netlib.org/lapack/explore-html/ 

 Definition:
 ===========

      LOGICAL FUNCTION DLAISNAN( DIN1, DIN2 )
 
      .. Scalar Arguments ..
      DOUBLE PRECISION   DIN1, DIN2
      ..
  

 Purpose:
 =============

 This routine is not for general use.  It exists solely to avoid
 over-optimization in DISNAN.

 DLAISNAN checks for NaNs by comparing its two arguments for
 inequality.  NaN is the only floating-point value where NaN != NaN
 returns .TRUE.  To check for NaNs, pass the same variable as both
 arguments.

 A compiler must assume that the two arguments are
 not the same variable, and the test will not be optimized away.
 Interprocedural or whole-program optimization may delete this
 test.  The ISNAN functions will be replaced by the correct
 Fortran 03 intrinsic once the intrinsic is widely available.

  Arguments:
  ==========

  [in] DIN1
          DIN1 is DOUBLE PRECISION

  [in] DIN2
          DIN2 is DOUBLE PRECISION
          Two numbers to compare for inequality.

 Authors:
 ========
   Univ. of Tennessee 
   Univ. of California Berkeley 
   Univ. of Colorado Denver 
   NAG Ltd. 

 November 2011

