Purpose
 
 Test whether a real value is finite.
 
  Synopsis
 
 function isfinite(r: real):boolean
 
  Argument
 
  Return value
 
 true if the value is neither
 
(-)INFINITY
  nor
 
NAN
 .
 
  Further information
 
  The call
 isfinite(v) is equivalent to
 (not isnan(v) and not isinf(v)).
 
  Related topics