8 % o = outer, i = inner, f = final
25 /stridox szox n div def
26 /stridoy szoy n div def
28 /szix stridox margox sub def
29 /sziy stridoy margoy sub def
31 /stridix szix knx div def
32 /stridiy sziy kny div def
34 /szfx stridix margix sub def
35 /szfy stridiy margiy sub def
37 0 1 m { /yellow exch def
38 0 1 m { /magenta exch def
39 0 1 m { /cyan exch def
44 cyan neg m add stridoy mul translate
48 0 1 kmx { /blackx exch def
49 0 1 kmy { /blacky exch def
60 blacky neg kmy add stridiy mul
76 /Helvetica findfont 18 scalefont setfont