a medium semicircle next to a medium semicircle
for i in range(HALF_INF):
    forward(EPS_DIST*2)
    left(EPS_ANGLE)
penup()
forward(8)
left(0.0)
pendown()
for i in range(HALF_INF):
    forward(EPS_DIST*2)
    left(EPS_ANGLE)