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FoataMajorToInversions ​

Foata's bijection: each letter is put on the end of the image so far, which is cut into blocks, and every block is rotated one place right.

FoataMajorToInversions(Permutation)Foata's bijection: each letter is put on the end of the image so far, which is cut into blocks, and every block is rotated one place right.
Typed signatures
TypePackageApplies
((binary_word) -> binary_word) & ((composition) -> composition) & ((permutation) -> permutation)combinatoricsalways

Domain: Combinatorial maps

Details
  • Takes a Permutation and returns a Permutation — a typed map, so a wrong carrier is a type error rather than a wrong answer.
  • FindStat's Mp00067, Sage's foata_bijection. It sends the major index to the number of inversions; the inverse is FoataInversionsToMajor. Not the cycle-based Foata, which is FindStat's first fundamental transformation.
  • Also takes a IntegerComposition, returning a IntegerComposition: Foata's bijection on the word of parts: each part is put on the end of the image so far, which is cut into blocks, and every block is rotated one place right.
  • FindStat's Mp00314. An equal part counts as the smaller; it sends the major index to the number of inversions.
  • Also takes a BinaryWord, returning a BinaryWord: Foata's bijection on words: each letter is put on the end of the image so far, which is cut into blocks, and every block is rotated one place right.
  • FindStat's Mp00096. With repeated letters an equal letter counts as the smaller, so it is the permutation map through standardization; it sends the major index to the number of inversions.

Examples

Basic #

the one-line word 231231

live ↗
InFoataMajorToInversions(Permutation⁡([2,3,1]))\mathrm{FoataMajorToInversions}({\operatorname{Permutation}}([2, 3, 1]))OutPermutation⁡([2,3,1]){\operatorname{Permutation}}([2, 3, 1])

the composition 2+1+32 + 1 + 3

live ↗
InFoataMajorToInversions(IntegerComposition⁡([2,1,3]))\mathrm{FoataMajorToInversions}({\operatorname{IntegerComposition}}([2, 1, 3]))OutIntegerComposition⁡([2,1,3]){\operatorname{IntegerComposition}}([2, 1, 3])

the binary word 0110001100

live ↗
InFoataMajorToInversions(BinaryWord⁡([0,1,1,0,0]))\mathrm{FoataMajorToInversions}({\operatorname{BinaryWord}}([0, 1, 1, 0, 0]))OutBinaryWord⁡([0,1,0,1,0]){\operatorname{BinaryWord}}([0, 1, 0, 1, 0])
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Examples3
CrosswalkFindStat ×3