A Program for the MIU Puzzle

I have recently uploaded a Perl program for the MIU puzzle (from Gödel, Escher, Bach by Douglas Hofstadter) to my Earthlink/Netcom site. It will take a string to be derived on the command line and either produce a derivation or an explanation why there is no derivation.

For example, the command line:

perl miu.pl MUIIU

will produce the derivation:

0:      Axiom: MI
1:      Rule 2: MII
2:      Rule 2: MIIII
3:      Rule 2: MIIIIIIII
4:      Rule 3: MIIIIIU
5:      Rule 3: MUIIU

and the command line:

perl miu.pl MU

will produce the explanation:

The total number of Is in an entry must not be divisible by 3.