startshape WHOLE

rule WHOLE {

QUAD { x -0.5 y -0.5 }
QUAD { x  0.5 y -0.5 }
QUAD { x  0.5 y  0.5 }
QUAD { x -0.5 y  0.5 }

}

rule QUAD {

FILL { }

} rule QUAD 5 {

WHOLE { size 0.45 r 2 }

} rule QUAD 0.5 {

// nothing

}

rule FILL {

SQUARE {
        size 0.8
}

}