Context
A state quotient can merge transitions but cannot delete a self-loop already carried by one member of a block.
Hypotheses and scope
- The quotient uses existential block transitions.
Proof or evidence
If q has a σ-loop, the source and target of that edge both lie in π(q), so the quotient definition creates the same labelled loop on π(q).
Verification notes
The one-line proof and the quotient convention were checked against every computational benchmark.
Limitations
- The statement does not cover quotient notions that are allowed to delete transitions.
- No novelty is claimed for loop preservation itself.