:import std/Combinator .
:import std/List .
:import Screen .

t-square-1 [[build tl tr bl br] mut]
	mut y* ([[[[build 3 2 1 b]]]] : ([[[[build 3 2 b 0]]]] : ([[[[build 3 b 1 0]]]] : {}[[[[build b 2 1 0]]]])))
	tl ^0
	tr ^(~0)
	bl ^(~(~0))
	br ^(~(~(~0)))

t-square-2 [[build tl tr bl br] mut]
	mut y* ([[[[build 3 2 1 (build b w w b)]]]] : ([[[[build 3 2 (build w b b w) 0]]]] : ([[[[build 3 (build w b b w) 1 0]]]] : {}[[[[build (build b w w b) 2 1 0]]]])))
	tl ^0
	tr ^(~0)
	bl ^(~(~0))
	br ^(~(~(~0)))

sierpinski-carpet [[build tl tr bl br] mut]
	mut y* ([[[[build 3 2 1 (build (build b w w w) w w b)]]]] : ([[[[build 3 2 (build w (build w b w w) b w) 0]]]] : ([[[[build 3 (build w b (build w w b w) w) 1 0]]]] : {}[[[[build (build b w w (build w w w b)) 2 1 0]]]])))
	tl ^0
	tr ^(~0)
	bl ^(~(~0))
	br ^(~(~(~0)))

sierpinski-triangle [y [build 0 b 0 0]]