getarity
| getarity | 
  Purpose
 
 Returns the number of decision variables involved in the constraint; this function can be used, for instance, to design advanced search heuristics
 
  Synopsis
 
function getarity(ctr:cpctr) : integer
 
  Argument
 
| 
     ctr 
     | 
     the constraint to explore
     | 
  Return value
 
 The number of variables involved in ctr
  Example
 
 The following example shows how to get the arity of a constraint
 
getarity(x + y = 3)
 
