def dense(width, height):
 d = {('x', 0, i): i for i in range(width)}
 for j in range(1, height):
  d.update({('x', j, i): (noop, [('x', (j - 1), k) for k in range(width)]) for i in range(width)})
 return (d, [('x', (height - 1), i) for i in range(width)])

def dense ( width , height ) : d = { ( 'x' , 0 , i ) : i for i in range ( width ) } for j in range ( 1 , height ) : d . update ( { ( 'x' , j , i ) : ( noop , [ ( 'x' , ( j - 1 ) , k ) for k in range ( width ) ] ) for i in range ( width ) } ) return ( d , [ ( 'x' , ( height - 1 ) , i ) for i in range ( width ) ] )
full barriers between each step .