2 <FUNCTION TL ("STACK" START FINISH)
3 <PROG ("STACK" (VAL <FAILPOINT () <PATH1 .START .FINISH ()>
11 <FUNCTION ("STACK" START FINISH AVOID)
12 <COND (<==? .START .FINISH>
14 (<MEMBER .START .AVOID>
18 <FAILPOINT FP ("STACK" N (NODES <GET .START CONNECTED>))
20 <COND (<EMPTY? .NODES> <FAIL>)
22 <SET NODES <REST .NODES>>
25 (.START !.AVOID)>))>> >
\e
28 <PUT ALPHA CONNECTED (B D K)>
\e
29 <PUT B CONNECTED (ALPHA I C)>
\e\r\r
30 <PUT I CONNECTED (B H J)>
\e
31 <PUT H CONNECTED (I)>
\e
32 <PUT J CONNECTED (I)>
\e
33 <PUT C CONNECTED (B G D)>
\e
34 <PUT G CONNECTED (C)>
\e
35 <PUT D CONNECTED (ALPHA C F)>
\e
36 \r<PUT F CONNECTED (D)>
\e
37 <PUT K CONNECTED (ALPHA M L)>
\e
38 <PUT M CONNECTED (K L N O)>
\e
39 <PUT L CONNECTED (K M)>
\e
40 <PUT N CONNECTED (M)>
\e
41 <PUT O CONNECTED (M P OMEGA)>
\e
42 <PUT P CONNECTED (O)>
\e
43 <PUT OMEGA CONNECTED (O)>
\e\f\ 3\f