# Exercise scaffold. Reference implementation is in a separate directory."""W07: a complete DFA comparison, not an arbitrary program-equivalence solver."""fromcollectionsimportdequedefvalidate(machine,alphabet):raiseNotImplementedError('Implement this contract from the book.')defdistinguishing_word(left,right,alphabet=('a','b')):raiseNotImplementedError('Implement this contract from the book.')defaccepts(machine,word):raiseNotImplementedError('Implement this contract from the book.')