make "description [Circles; from "Logo for the Apple II", pgs. 53-55]
define "rcp [[ :r][right 5][forward :r * 3.14159 / 18][right 5]]
define "lcp [[ :r][left 5][forward :r * 3.14159 / 18][left 5]]
define "rarc [[ :r][repeat 9 [rcp :r]]]
define "larc [[ :r][repeat 9 [lcp :r]]]
define "rcircle [[ :r][repeat 36 [rcp :r]]]
define "lcircle [[ :r][repeat 36 [lcp :r]]]
define "shrinkcircle [[ :size][if :size < 4 then stop][rcircle :size][shrinkcircle :size - 4]]
define "rslinky [[ :size][rcircle :size][pu][rt 90][fd 10][lt 90][pd][rslinky :size]]
define "spinslink [[ :size][rcircle :size][right 20][print heading][if heading = 0 then stop][spinslink :size]]
define "growcircle [[ :size][repeat 12 [rcp :size]][growcircle :size + 5]]