SimpleProjectiveDimensionProduct
The product of the nonzero projective dimensions of the simple modules of the path's linear Nakayama algebra.
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St001299via DyckPath✓SimpleProjectiveDimensionProduct(path)The product of the nonzero projective dimensions of the simple modules of the path's linear Nakayama algebra.Typed signatures
| Type | Package | Applies |
|---|---|---|
(dyck_path) -> number | combinatorics | always |
Details
- Defined over
DyckPathas an expression in_x, evaluated by compute-engine — the definition IS the implementation. - Takes a
DyckPathand 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 DyckPath, over _x
0 if Length(_x) < 1 else Apply(
(series: list<integer>) => Apply(
(dims: list<integer>) => Product(Map(Function(1 if d == 0 else d, d), dims)),
Map(
Function(Fold(
Function(Apply(
(entry: integer) => [a[1], a[2], a[3]] if a[2] == entry else [a[1] + a[2], entry - a[2], a[3] + 1],
series[a[1] + 1],
), a, b),
[v - 1, 1, 0],
Range(1, Length(_x) / 2 +
1),
)[3], v),
Range(
1,
Length(_x) /
2 +
1,
),
),
),
Apply(
(h: list<integer>) => Apply(
(ups: list<integer>) => Join(Map(
Function(h[ups[Length(_x) / 2 +
1 -
t]] +
1, t),
Range(1, Length(_x) / 2),
), [1]),
Filter(
Range(1, Length(_x)),
Function(_x[i] == 1, i),
),
),
Map(
Function(Sum(Map(
Function(
2 *
_x[k] - 1,
k,
),
Range(1, i),
)), i),
Range(1, Length(_x)),
),
),
)Examples
Properties #
About
| Examples | 5 |
|---|---|
| Crosswalk | FindStat |