Challenge: one-sided Kummer reciprocity for locally-primary pseudo-units #
The destination proves that the canonical Kummer radicand has p-divisible
finite divisor and is a p-th power in the completion at the cyclotomic
prime. It also checks the comparison between Kummer/Frobenius coordinates,
clears prime-to-cyclotomic fractional denominators to integral ones, and
removes the cyclotomic-prime factor itself. The sole remaining arithmetic
contract is therefore integral one-sided Kummer reciprocity for a
locally-primary pseudo-unit.
The checked bridges then prove prime-to-cyclotomic and full principal reciprocity, the Kummer product formula, and the required surjective inverse-cyclotomic ideal-class quotient. The separate Herbrand--Kummer assertion that this quotient cannot exist is not part of this contract.
One-sided Kummer reciprocity kills every integral principal Kummer symbol away from the cyclotomic prime when the radicand is a locally-primary pseudo-unit.
Checked reduction from the locally-primary pseudo-unit contract to prime-to-cyclotomic principal Artin reciprocity.
Checked reduction from prime-to-cyclotomic reciprocity to the full Kummer product formula.
Checked bridge from the exact Kummer product-formula contract to the roadmap-facing class-field-theory principle.