'abs' and 'distance' constraints

(!****************************************************************
   CP example problems
   ===================
   
   file distance.mos
   `````````````````
   Abs and distance constraints.

   (c) 2008 Artelys S.A. and Fair Isaac Corporation
       Creation: 2005, rev. Mar. 2013
*****************************************************************!)
model "Distance constraints"
 uses "kalis"
 
 setparam("KALIS_DEFAULT_LB", -50); setparam("KALIS_DEFAULT_UB", 50)

 declarations
  x, y, z: cpvar
  Dist: cpctr
 end-declarations  
  
 setname(x,"x")
 setname(y,"y")
 setname(z,"z")

 abs(x) = y
 writeln("Absolute value of x: ", x,y,z)

 y >= 20
 writeln("Bounding y by 20: ", x,y,z)
  
! abs(y-z) <= 3
! Equivalent version of this constraint:
 distance(y,z) <= 3

 writeln("Max distance betw. y and z: ", x,y,z)
 
 Dist:= distance(x,z) = 5
 
 if(cp_post(Dist)) then
  writeln("Distance between x and z: ", x,y,z) 
 else
  writeln("Problem is infeasible")
 end-if
 
 cp_show_prob

end-model