The program lim draws the orbits of circles
under the action of a group of Mobius transformations.

Usage:
lim [options]
    -a [agree] circles are regarded the same if center
       and radius differ by less than epsilon/agree.
    -b put box around image
    -c [c.x c.y r] clipping circle 
    -d [depth] - generations
    -e [epsilon] - radius of circles to ignore
    -h [huge-radius] huge cutoff radius
    -l [linewidth] - in 1/72nd of inch
    -m [maximum] number of circles to draw
    -q quiet
    -s plot on sphere
    -t [gray] make sphere transparent.  Circles
       on the back colored gray (0-1.0).
    -w [xmin ymin xmax ymax] window 
    < data.file
    > postscript.file

Entries in the data.file are of the following forms:

c center-x center-y radius
	for circle in the limit set
r center-x center-y radius
	for reflection in the group
m ax ay bx by cx cy dx dy
	for mobius transformation in the group
t ax ay bx by cx cy dx dy
	for mobius transformation to be applied
	to the coordinate system
u cx cy r
	for reflection in a circle to be applied
	to the coordinate system

# cusp.run file from Lim Version 2.2 by Copyright (c) 2001 Curtis T McMullen
#
# Classic maskit boundary picture:  on sphere
#
# mu=1.91I 0.05 
#
./lim -s -d 60 -e 0.0001 <<eof > cusp.ps
c 0. 0. 1
m 1 1 0 1 0 -1 1 -1
m 1 -1 0 -1 0 1 1 1
m 0.955 -0.025 0.045 0.025 -1.955 0.025 0.955 -0.025
m 0.955 -0.025 -0.045 -0.025 1.955 -0.025 0.955 -0.025
eof

pstopnm -xborder=0 -yborder=0 -xsize=1000 -ysize=1000 cusp.ps
pnmtopng cusp001.ppm >cuspb.png

convert cusp.png cusp.svg