The slot pairing #
The flag enumeration sends the fragment pairing to the straight
cap matching: the two flags of the i-th canonical edge sit at
slots i and edgeCount + i. The general-flag glue for the
Eulerian reindex.
The rep slot carries the canonical representative.
The partner slot carries the paired flag.
theorem
RS.pairing_starFlagEnum_symm
(W : ClosedFragment)
(i : Fin (edgeCount W))
:
W.pairing ((starFlagEnum W).symm (Fin.castAdd (edgeCount W) i)) = (starFlagEnum W).symm (Fin.natAdd (edgeCount W) i)
The slot pairing: the fragment pairing links slot i
to slot edgeCount + i.