DescentTopWord

Letter v - 1 is 1 when value v is a descent top: some smaller value immediately follows it.

FindStatMp00130via Permutation↗

DescentTopWord(Permutation)Letter v - 1 is 1 when value v is a descent top: some smaller value immediately follows it.

Typed signatures

Type	Package	Applies
(permutation) -> binary_word	combinatorics	always

Domain: Combinatorial maps

Details

• Takes a Permutation and returns a BinaryWord — a typed map, so a wrong carrier is a type error rather than a wrong answer.
• Value 1 is never a descent top, so the first letter stands for 2.

Examples

Basic #

the one-line word $231$

live ↗

In$\mathrm{DescentTopWord}({\operatorname{Permutation}}([2, 3, 1]))$Out${\operatorname{BinaryWord}}([0, 1])$

About

Examples	1
Crosswalk	FindStat