(!******************************************************
   Mosel User Guide Example Problems
   ================================= 

   file arcpkg.mos
   ```````````````
   Definition of the type 'arc'.
   
   (c) 2008 Fair Isaac Corporation
       author: S. Heipcke, Jan. 2007, rev. June 2018
*******************************************************!)

package arcpkg

 public declarations
  arc = public record                   ! Arcs:
   Source,Sink: string                  !   Source and sink of arc
   Cost: real                           !   Cost coefficient
  end-record 
 end-declarations

(! Alternatively:
 declarations
  public arc = record                   ! Arcs:
   public Source,Sink: string           !   Source and sink of arc
   public Cost: real                    !   Cost coefficient
  end-record 
 end-declarations
!)

 public function is_neighbor(n1,n2: string, A: array(Arcs:set of integer) of arc): boolean
(!  
  returned:=or(a in Arcs ) ((A(a).Source=n1 and A(a).Sink=n2) or
                            (A(a).Source=n2 and A(a).Sink=n1))
!)
  returned:= or(a in Arcs, source=A(a).Source, sink=A(a).Sink) 
                ((source=n1 and sink=n2) or (source=n2 and sink=n1))
 end-function  

end-package