anchor.diff:        integer i2,i3,j3,ik
         integer fn_out
         logical ofound,omatch
  -
  +      character*73 message
  +
  +      message = "opening file"
         fn_out = 33
          open(unit=fn_out,file="fourimer.dat",
        $            form='formatted',status='unknown',err=911)
  
positive.code:        n2 = nres*(nres-1)/2
         allocate(p2(2,n2))
         call parse_dimers(nres,cg,n2,p2)
         n3 = 1000
         allocate(p3(3,n3))
         call parse_trimers(n2,p2,n2,2,p2,n3,p3)
  c       do i=1,n3
  c         write(*,*) (p3(il,i),il=1,3)
  c       end do
         allocate(p4(4,n4))
         call parse_fourmers(n2,p2,n3,3,p3,n4,p4)
         do i=1,n4
           write(*,*) (p4(il,i),il=1,4)
         end do
  !      == deallocate arrays ==
         deallocate(p2)
         deallocate(cg)
         deallocate(ir)
  
negative.code:       if(buffer.eq." ") istatus = 1
  c      call get_command_argument(i,buffer,l,istatus)
        end subroutine
  
        subroutine parse_trimers0(nb2,p2,nb,l,p,px)
        implicit none
  