928 — The Rank-Two Normal-Symbol Module Is Not Closed Under Serialized Differentiation
Connection-existence gate
Entry 927 proves that the kernel relation
is constant. It does not prove that the rank-two image generated by two branch symbols is preserved by tangential differentiation. Before constructing a connection matrix, closure must be tested.
Tensor form of the symbol module
After the frozen Cartier regularizations, the three symbols have the form
where the target vectors span rank two and the source row spans rank one. Therefore
For a tangential derivative ,
If and are projectively independent, the derivative closure has rank .
Exact closure test
Entry 927's projective Wronskians are nonzero for every tested tangential variable:
For each variable, three Wronskians are nonzero. Hence
and
Thus
in the serialized transition frame.
Consequence
No canonical rank-two tangential connection can be extracted from the transition matrix alone. Doing so would require one of:
- the independently derived ambient connection on the six-word source bundle;
- a source-derived projection back to ;
- a larger derivative-closed coefficient module.
Choosing a complement or projection by sparsity would be post hoc.
The constant syzygy remains valid: it is a relation in the kernel of the branch presentation. What fails is closure of its rank-two image under the bare serialized derivative.
Narrow conclusion
The current object is
It is not yet a rank-two local system. This is a coefficient-typing obstruction, not evidence for a new carrier stratum.
Next falsifier
Locate or derive the ambient tangential connection on the frozen six-word source basis and test whether its covariant derivative preserves . If it does, descend the connection to . If it does not, compute the full minimal covariant closure rather than projecting back by choice.