BinarySearchTreeParentArray from Permutation
The binary search tree of σ as its parent array: entry v is the value v is inserted under, 0 for the root.
A search tree's values are its in-order labels, so this is the tree's in-order parent array. See bst.ts for why a fold builds it this way.
Called as CombinatorialMap(x, "BinarySearchTreeParentArray"). The head's page has its examples.
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Each element of Permutation at a size, and its image, applied in your browser; sizes past 7 are not offered.
Properties
Transport a statistic
Pick a statistic on BinaryTreeParentArray. Its distribution over the images of Permutation at each size is computed, and compared with the 323 statistics on Permutation: those that share it are the ones the map sends it to, as far as the sizes computed show.
No statistic is declared on BinaryTreeParentArray.