The triangle scalar of the power chain #
The copairing powers of a duality datum retract against the nested power pairing: under the scalar zigzag, the pairing evaluates every chain unit to the unit of the base. This is the nonvanishing engine of the Key Lemma's chain.
The braiding of the module tensor product is natural.
The nested pairing at arity one is the pairing, through the singleton isomorphisms.
The Mod-internal power pairing at arity zero is the datum's pairing, through the singleton stages.
The seed retracts against the pairing: under the scalar zigzag, the bottom chain unit evaluates to the unit of the base.
The module-power projection is an epimorphism.
The tensor product of two module-power projections is an epimorphism.
A tensor pair of power projections whiskered on the right is an epimorphism.
A tensor square of power projection pairs is an epimorphism.
A left-whiskered power projection whiskered on the right is an epimorphism.
The interchange followed by a functorial map computes under the stage projections: the raw crossing feeds the two module maps.
The interchange followed by a functorial map computes under the stage projections: the raw crossing feeds the two module maps.
Multiplicativity of the pairing against the transition core: the interchange followed by the aligned multiplications and the pairing of the joined stage evaluates as the product of the stage pairings.
The transition retracts against the pairing: under the scalar zigzag, one insertion peels off against one zigzag.
The chain units retract against the pairing: every copairing power evaluates to the unit of the base.
Scalar extraction at the head of the M'-power: the tail
action on the M'-power extracts as the scalar multiplying the
pairing from the left.
The head action extracts through the descended pairing.
The power pairing is linear: it is a map of modules into the regular module.