name: palindromes over a,b, two-tape machine
init: copy
accept: accept


copy, a, _
copy, a, a, >, > 

copy, b, _
copy, b, b, >, > 

copy,   _, _
rewind, _, _, <, - 


rewind, a, _ 
rewind, a, _, <, -

rewind, b, _ 
rewind, b, _, <, -

rewind,  _, _ 
compare, _, _, >, < 

compare, a, a 
compare, a, a, >, < 

compare, b, b 
compare, b, b, >, < 

compare, _, _ 
accept, _, _, >, <