RS21's summand, at a prescribed circuit count #
edgeSum is RS21's colouring sum; s_h(F,H,ω,κ) is that sum with
the circuit sign in front. The composition carries its own count
from stage to stage — an open glue may or may not close a circuit,
and settling that is the ledger's business, not the colouring's — so
the summand is named here with the count as a parameter, extended by
zero off the good subsets, exactly as termAt is.
Transporting the colouring sum along an equality of subsets.
RS21's summand at a prescribed circuit count.
Equations
- One or more equations did not get rendered due to their size.
Instances For
The summand vanishes off edge-closed flag sets.
And off subsets that do not match the boundary state.
And off non-Eulerian subsets.
And off subsets carrying no canonical datum — so the sum runs over the good subsets only.
The summand at a good subset.
One open cut #
The boundary state's colour at the cut is even exactly when the subset misses it, so the sum over that colour runs over one block and is the glued fragment's summand.
A missed cut admits no odd colour at the interface.
A carried cut admits no even colour at the interface.
On a missed cut the even extensions all match.
On a carried cut the odd extensions all match.
The base's summand at an open lift is the glued fragment's data, unglued.
One open cut, on RS21's summands. The interface colour is even exactly when the subset misses the cut, so the sum over it is the glued fragment's summand.
One open cut, with nothing assumed of the subset #
The iteration sums over every subset of the glued fragment, so the cut's identity is needed with no hypothesis on it. Off the good subsets both sides vanish — and where the glue's closure fails, what kills the lift is the interface state's own diagonality: the lift would hold one glued flag and not the other, and so want the state odd at one label and even at the other.
A diagonal state forces the glue's closure.
One open cut, with nothing assumed of the subset.
One closing cut #
Gluing an edge with both ends labelled leaves a free circle. On the
base the edge is a trail from one label to the other and carries no
circuit; in the composition it is a circuit, and the ledger records
that as the extra count the carried branch is taken at. The two
branches then weigh k and −2ℓ, which is the circle's own value.
The empty branch admits no odd colour at the cut.
The carried branch admits no even colour at the cut.
On the empty branch the even extensions all match.
On the carried branch the odd extensions all match.
The base's summand at a closed lift is the glued fragment's data, unglued.
The empty branch of a closing cut weighs k. Only the even
colours reach it — the odd ones would ask for the cut's own edge —
and each of them gives the glued term back.
The carried branch of a closing cut weighs −2ℓ. Only the
odd colours reach it, and each of them gives the glued term back with
the sign the extra carried cut supplies.
One closing cut, on RS21's summands. The two branches of the
closed edge weigh k and −2ℓ, the free circle's own value.
One closing cut, with nothing assumed of the subset #
The glued boundary constraint from the lift's.
A closed lift's closure is the glue's.
One closing cut, with nothing assumed of the subset.
The empty branch of a closing cut weighs k, with nothing
assumed of the subset.
The carried branch of a closing cut weighs −2ℓ, with
nothing assumed of the subset.
RS21's sum over a disjoint union #
The two halves of a composition colour their own edges, and a through-edge of the union is a through-edge of one of them, so the agreement splits with the sum.
The named colour of a left flag is the left half's.
The named colour of a right flag is the right half's.
Agreement restricts to the left half.
Agreement restricts to the right half.
Agreement on both halves is agreement.
RS21's colouring sum splits over a disjoint union.
RS21's sum under a relabel #
The composition's stages relabel the surviving interface, and the colouring sum does not see the labels beyond the boundary match.
The odd boundary constraint reindexes through the relabel.
The odd colourings are the same on both sides of a relabel: the flags and the pairing are untouched.
Equations
- RS.EdgeSubset.edgeOddRelabelEquiv ee F ℓ = Equiv.refl ((RS.EdgeSubset.relabelUp ee F).EdgeOddColouring ℓ)
Instances For
The core of a relabelled colouring is the relabelled core.
RS21's colouring sum is untouched by a relabel.
The data family pulled back along a relabel.
Equations
- One or more equations did not get rendered due to their size.
Instances For
RS21's summand is untouched by a relabel.