Example illustrating how subroutines can be used
inside a TM program.  By cutting and modifying
the first line to point at a particular sub-routine,
one can choose between any of:
o unary string copier
o unary string squarer
o unary string multiplier


SQUARE SUBROUTINE:  #111 ---> #111111111
                     ^         ^
1,#,20,>

COPIER:  ?111 ---> ?111222
          ^         ^
20,1,21,a,>
20,2,23,<
21,1,21,>
21,2,21,>
21,_,22,2,<
22,1,22,<
22,2,22,<
22,a,20,>
23,a,23,1,<
23,#,30,>
23,2,31,<


MULTIPLIER SUBROUTINE: #11122222 ---> #111111111111
                        ^              ^
30,2,30,1,>
30,1,30,2,>
30,_,31,<
31,1,31,<
31,2,31,<
31,#,33,>
31,2,31,<
31,b,33,>
33,2,34,b,>
34,2,34,>
34,1,35,<
35,2,20,>
35,b,40,>
40,1,40,>
40,2,40,1,>
40,_,41,<
41,1,42,_,<
42,1,42,<
42,b,43,1,<
43,b,40,>
43,#,99,X