startshape x4x

tile {s 54}

rule R {SQUARE{}2*{f 45}R{s.6 1r-90x 2y 1}}

rule x4x {

2 * {s .5 x 9 y 9 b .2}
{4*{r 90 x 36}
R {}
SQUARE {s 17.2 x 18 y 18 b .6 z -1}}
2 * {s .5 x -4.5 y -4.5 z 1 b 1}
SQUARE {s 16.7 x -9 y -9 z -1 b .5}

}