The colouring correspondence at one cut #
RS21 glues two open ends by removing the two labelled vertices and joining the two edges into one, so a colouring of the glued graph is a colouring of the two halves that agrees at the join — and the colour at the join is exactly the interface state's colour there. Summing the halves' colouring sums over that colour is therefore the glued graph's own colouring sum.
This file proves that, one cut at a time, for RS21's colouring sum
edgeSum. The two ends of the cut are either both outside the
subset, when the join carries an even colour, or both inside it,
when it carries an odd one; the sum over the state's colour at the
cut runs over the corresponding block.
The cut the subset misses #
Neither glued flag is in the subset, so the join carries an even colour and the subset's own flags are the glued fragment's, unchanged.
The i-flag is out of the lift.
The j-flag is out of the lift.
A flag of the lift survives the glue.
A flag of the lift, as a flag of the glued fragment.
Equations
- RS.EdgeSubset.survOfLift hij hopen t hct hni hf = ⟨f, ⋯⟩
Instances For
A flag of the lift, read as a glued flag, lies in the glued subset.
Conversely a glued subset flag's underlying flag lies in the lift.
Odd colourings agree across a missed cut. The cut's own edge is outside the subset, so the two sides colour the same edges.
Equations
- One or more equations did not get rendered due to their size.
Instances For
The odd boundary constraint matches across a missed cut.
The odd colouring sum transports across a missed cut.
One missed cut, on RS21's colouring sums. The join carries an even colour, and that colour is the glued colouring's own at the far end of the cut — so the sum over it has a single term.
The cut the subset carries #
Both glued flags are in the subset, so the join carries an odd colour; the even colourings are the same on both sides and the sum over the join's colour is absorbed by the odd ones.
The i-flag is in the lift.
The far end of the j-edge is in the subset too.
The j-flag is in the lift.
A flag outside the lift survives the glue.
A flag outside the lift, as a flag of the glued fragment.
Equations
- RS.EdgeSubset.survOfNotLift hij hopen t hct hpi hf = ⟨f, ⋯⟩
Instances For
A flag outside the lift, read as a glued flag, lies outside the glued subset.
Conversely a flag outside the glued subset has its underlying flag outside the lift.
Away from the interface the glued pairing is the base's.
Even colourings agree across a carried cut. The cut's own edge is in the subset, so the two sides colour the same complement.
Equations
- One or more equations did not get rendered due to their size.
Instances For
The glued colouring is constant across the join.
The pushed colouring's value at a flag of the lift.
Equations
- One or more equations did not get rendered due to their size.
Instances For
At the first glued boundary flag the pushed colouring takes the join's colour.
At the second it takes the same colour: the two ends of the join are one edge after gluing.
Away from the two glued flags the pushed colouring is the colouring it was pushed from.
Push a glued odd colouring up to the lift, colouring the two glued flags with the join's own colour.
Equations
- RS.EdgeSubset.oddPushHit hij hopen t hct hcL hpi φ' = ⟨RS.EdgeSubset.oddPushHitFun hij hopen t hct hpi φ', ⋯⟩
Instances For
The odd boundary constraint across a carried cut. It pins the join's colour to the state's, and is the glued constraint otherwise.
The push is injective.
Every colouring meeting the join's constraint is a push.
The even boundary constraint across a carried cut.
The odd colouring sum is a sum over the glued colourings.
One carried cut, on RS21's colouring sums. The join carries an odd colour, and that colour is the glued colouring's own there — so again the sum over it has a single term.
The cut that closes #
Gluing an edge whose two ends are both labelled removes it and leaves a free circle. RS21 records this explicitly; the colourings see it as two blocks — the edge outside the subset, carrying an even colour, and inside it, carrying an odd one — each of which is the glued fragment's colouring sum over again.
The i-flag is out of the empty lift.
The j-flag is out of the empty lift.
A flag of the empty lift survives the glue.
A flag of the empty lift, as a flag of the glued fragment.
Equations
- RS.EdgeSubset.survOfLiftClosedFalse hij t hf = ⟨f, ⋯⟩
Instances For
A glued subset flag's underlying flag lies in the untaken closed lift.
A flag of the untaken closed lift lies in the glued subset.
Odd colourings agree across a closing cut the subset misses.
Equations
- One or more equations did not get rendered due to their size.
Instances For
The odd boundary constraint matches across a closing cut the subset misses.
The pushed even colouring's value at a flag outside the lift.
Equations
- RS.EdgeSubset.evenPushClosedFalseFun hclosed t hct a ψ' f = if hfi : ↑f = V.boundaryFlag i then a else if hfj : ↑f = V.boundaryFlag j then a else ↑ψ' ⟨⟨↑f, ⋯⟩, ⋯⟩
Instances For
At the first glued boundary flag the pushed even colouring takes the summation colour.
At the second it takes the same colour.
Away from the two glued flags the pushed even colouring is unchanged.
Push a glued even colouring up to the lift, colouring the closed edge with the join's colour.
Equations
- RS.EdgeSubset.evenPushClosedFalse hij hclosed t hct hcL a ψ' = ⟨RS.EdgeSubset.evenPushClosedFalseFun hclosed t hct a ψ', ⋯⟩
Instances For
The push is injective.
The even boundary constraint across a closing cut the subset misses.
Every colouring meeting the join's constraint is a push.
The even colouring sum is a sum over the glued colourings.
A closing cut the subset misses, on RS21's colouring sums.
The closed edge carries the join's even colour and nothing else
changes, so each of the k colours reproduces the glued sum.
The i-flag is in the carried lift.
The j-flag is in the carried lift.
A flag outside the carried lift survives the glue.
A flag outside the carried lift, as a glued flag.
Equations
- RS.EdgeSubset.survOfNotLiftClosedTrue hij t hf = ⟨f, ⋯⟩
Instances For
A flag outside the taken closed lift lies outside the glued subset.
A glued subset flag's underlying flag lies in the taken closed lift.
And a flag outside the glued subset lies outside it.
Even colourings agree across a closing cut the subset carries.
Equations
- One or more equations did not get rendered due to their size.
Instances For
The even boundary constraint across a closing cut the subset carries.
The pushed odd colouring's value at a flag of the carried lift.
Equations
- RS.EdgeSubset.oddPushClosedTrueFun hclosed t hct d φ' f = if hfi : ↑f = V.boundaryFlag i then d else if hfj : ↑f = V.boundaryFlag j then d else ↑φ' ⟨⟨↑f, ⋯⟩, ⋯⟩
Instances For
At the first glued boundary flag the pushed odd colouring takes the circle's colour.
At the second it takes the same colour.
Away from the two glued flags the pushed odd colouring is unchanged.
Push a glued odd colouring up to the carried lift, colouring the closed edge with the join's colour.
Equations
- RS.EdgeSubset.oddPushClosedTrue hij hclosed t hct hcT d φ' = ⟨RS.EdgeSubset.oddPushClosedTrueFun hclosed t hct d φ', ⋯⟩
Instances For
The push is injective.
The odd boundary constraint across a closing cut the subset carries.
Every colouring meeting the join's constraint is a push.
The odd colouring sum is a sum over the glued colourings.
A closing cut the subset carries, on RS21's colouring sums.
The closed edge carries the join's odd colour and nothing else
changes, so each of the 2ℓ colours reproduces the glued sum.