next | previous | forward | backward | up | top | index | toc | Macaulay2 website

Posets :: joinIrreducibles

joinIrreducibles -- determines the join irreducible elements of a poset

Synopsis

Usage:

J = joinIrreducibles P
Inputs:
- P, an instance of the type Poset
Outputs:
- J, a list

Description

An element $a$ of $P$ is join irreducible if it is not the join of any set of elements not containing $a$.

i1 : joinIrreducibles booleanLattice 3

o1 = {000, 001, 100, 010}

o1 : List

See also

joinExists -- determines if the join exists for two elements of a poset
meetIrreducibles -- determines the meet irreducible elements of a poset
posetJoin -- determines the join for two elements of a poset

Ways to use `joinIrreducibles` :

"joinIrreducibles(Poset)"

For the programmer

The object joinIrreducibles is a method function.