Insertion and contraction on the multi-tensor #
The two workhorses of the Key Lemma's pairing calculus: inserting a copairing's image at a boundary of the multi-tensor, and contracting a pairing across one. Insertion needs no descent — it lands in the larger multi-tensor through the concatenation; contraction descends through the coequalizer using the pairing's linearity.
The pairing evaluated on the two-element fold.
Equations
- One or more equations did not get rendered due to their size.
Instances For
Case analysis for decompositions of Xs ++ [M', M]: a slot
lies inside Xs, at the boundary, or inside the pair.
The fold-level three-window contraction: pair off the trailing window, act on the head with the resulting scalar.
Equations
- One or more equations did not get rendered due to their size.
Instances For
The window morphism of the trailing pair passes to the pairing through the projection.
The boundary-slot condition of the three-window contraction: the two window legs of the head--dual boundary agree after the contraction, through the linearity of the pairing.
The multi-level contraction at a three-element window: a linear pairing contracts the trailing pair of the multi-tensor, the scalar acting on the head.
Equations
- RS.modMultiContract3 A p hp N = RS.modMultiDesc A (RS.contract3Fold A p N) ⋯
Instances For
Defining equation of the three-window contraction.
Defining equation of the three-window contraction.
The image of a copairing at the two-element multi-tensor.
Equations
Instances For
The zig composite of a copairing and a linear pairing: insert the copairing on the left, concatenate, and contract the trailing pair. The zigzag law of a duality datum states that this composite is the identity.
Equations
- One or more equations did not get rendered due to their size.