Context
Membership asks whether one target is generated, so a quotient need not distinguish pairs of non-target monoid elements.
Hypotheses and scope
- The restriction of to is a homomorphism and its generator images form a polynomial-size poDFA action.
- For every , the exact target-code condition holds; if , the fibre is empty.
- The observation is produced by a uniform polynomial-time construction whose fibre property is established mathematically.
Proof or evidence
Image membership is equivalent to original target membership by the exact target-code condition. Ryzhikov and Wolf's Proposition 9 shortens an image word to length at most |P|(|P|+1)/2, and word reversal transfers it from the opposite monoid back to M.
Verification notes
The proof was checked in both directions, including targets outside M. The revised statement never writes rho(f) unless f is known to be in the domain, and the construction requirement remains separate from merely guessing an image action.
Limitations
- This theorem does not construct the required observation and does not settle NP versus PSPACE-hardness.
- Efficient verification of an arbitrarily guessed fibre condition is not claimed.