   { [ separation-radius> in-range? ]
     [ separation-view-angle> in-view? ]
     [ eq? not ] }
-  <--&& ;
+  2&& ;
 
 : separation-neighborhood ( self -- boids )
   boids> [ within-separation-neighborhood? ] with filter ;

  { [ alignment-radius> in-range? ]
    [ alignment-view-angle> in-view? ]
    [ eq? not ] }
  <--&& ;

: alignment-neighborhood ( self -- boids )
boids> [ within-alignment-neighborhood? ] with filter ;

  { [ cohesion-radius> in-range? ]
    [ cohesion-view-angle> in-view? ]
    [ eq? not ] }
  2&& ;

: cohesion-neighborhood ( self -- boids )
  boids> [ within-cohesion-neighborhood? ] with filter ;
