Documentation

LeanPool.RegtsSevenster.RS.Classical.Deligne.Rappel210Chain

The local splitting chain #

The algebra of Deligne's 2.10: for a point of an object, the chain of plain symmetric powers with transitions multiplication by the point. The colimit is the quotient of the symmetric algebra identifying the point with the unit; the stages, the seed, the stage multiplication, and the stage units are pinned here, and the laws assemble the colimit into a commutative algebra through the generic chain kit.

Stage laws #

The transitions, the stage multiplication and the seed satisfy the five stagewise laws consumed by the chain kit, derived from the symmetric-multiplication laws one letter up. The arity transports over definitionally equal indices collapse to identities.