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IdentityMatchingEdgeCount ​

Pairs {2k - 1, 2k}: the edges shared with the matching 12, 34, 56, ....

✓ checked against that system · ! checked, with disagreements (hover a chip)FindStatSt001997via PerfectMatching✓
IdentityMatchingEdgeCount(partition)Pairs {2k - 1, 2k}: the edges shared with the matching 12, 34, 56, ....
Typed signatures
TypePackageApplies
(perfect_matching) -> numbercombinatoricsalways

Domain: Perfect matching statistics

Details
  • Defined over PerfectMatching as an expression in _x, evaluated by compute-engine — the definition IS the implementation.
  • Takes a PerfectMatching and nothing else — it reads values against their positions, or walks the orbits, so it needs the bijection. Applying it to a bare list is a type error, not a wrong answer.
  • FindStat's St001997. The identity matching is 12, 34, 56, ....

Definition

Epsil, as the implementation runs it.

on PerfectMatching, over _x

Count(Filter(_x, Function(b[1] % 2 == 1 && Last(b) - b[1] == 1, b)))

Examples

Basic #

the matching {1,4}∣{2,3}∣{5,6}\{1,4\} \mid \{2,3\} \mid \{5,6\}

live ↗
InIdentityMatchingEdgeCount(PerfectMatching⁡([[1,4],[2,3],[5,6]]))\mathrm{IdentityMatchingEdgeCount}({\operatorname{PerfectMatching}}([[1, 4], [2, 3], [5, 6]]))Out11
Properties #

FindStat's value for [(1,2)]

live ↗
InCombinatorialStat(PerfectMatching⁡([[1,2]]),IdentityMatchingEdgeCount)\mathrm{CombinatorialStat}({\operatorname{PerfectMatching}}([[1, 2]]), \text{IdentityMatchingEdgeCount})Out11

Known value · FindStat St001997

FindStat's value for [(1,2),(3,4)]

live ↗
InCombinatorialStat(PerfectMatching⁡([[1,2],[3,4]]),IdentityMatchingEdgeCount)\mathrm{CombinatorialStat}({\operatorname{PerfectMatching}}([[1, 2], [3, 4]]), \text{IdentityMatchingEdgeCount})Out22

Known value · FindStat St001997

FindStat's value for [(1,3),(2,4)]

live ↗
InCombinatorialStat(PerfectMatching⁡([[1,3],[2,4]]),IdentityMatchingEdgeCount)\mathrm{CombinatorialStat}({\operatorname{PerfectMatching}}([[1, 3], [2, 4]]), \text{IdentityMatchingEdgeCount})Out00

Known value · FindStat St001997

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