OccurrencesOf13Over24
Occurrences of the pattern 13/24: a < b < c < d with a, c in one block and b, d in another.
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St000559via SetPartition✓OccurrencesOf13Over24(partition)Occurrences of the pattern 13/24: a < b < c < d with a, c in one block and b, d in another.Typed signatures
| Type | Package | Applies |
|---|---|---|
(set_partition) -> number | combinatorics | always |
Details
- Defined over
SetPartitionas an expression in_x, evaluated by compute-engine — the definition IS the implementation. - Takes a
SetPartitionand 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.
Definition
Epsil, as the implementation runs it.
on SetPartition, over _x
0 if Length(Flatten(_x)) < 4 else Sum(Map(
Function(Sum(Map(
Function(Sum(Map(
Function(Count(Filter(
Range(c + 1, Length(Flatten(_x))),
Function(Sum(Map(
Function(q if Contains(_x[q], a) else 0, q),
Range(1, Length(_x)),
)) ==
Sum(Map(
Function(q if Contains(_x[q], c) else 0, q),
Range(1, Length(_x)),
)) &&
Sum(Map(
Function(q if Contains(_x[q], b) else 0, q),
Range(1, Length(_x)),
)) ==
Sum(Map(
Function(q if Contains(_x[q], d) else 0, q),
Range(1, Length(_x)),
)) &&
Abs(Sum(Map(
Function(q if Contains(_x[q], a) else 0, q),
Range(1, Length(_x)),
)) -
Sum(Map(
Function(q if Contains(_x[q], b) else 0, q),
Range(1, Length(_x)),
))) >
0, d),
)), c),
Range(b + 1, Length(Flatten(_x)) - 1),
)), b),
Range(
a + 1,
Length(Flatten(_x)) -
2,
),
)), a),
Range(1, Length(Flatten(_x)) - 3),
))Examples
Properties #
About
| Examples | 5 |
|---|---|
| Crosswalk | FindStat |