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Macaulay2 web site
Posets
::
posetJoin
posetJoin -- determines the join for two elements of a poset
Synopsis
Usage:
j = posetJoin(P, a, b)
Inputs:
P
,
an object of class
Poset
a
,
a
thing
, an element of the poset
b
,
a
thing
, an element of the poset
Outputs:
j
,
a
thing
, the least element greater than both
a
and
b
, if it exists
Description
The join of
a
and
b
in
P
, if it exists, is the unique least element greater than both
a
and
b
.
i1 : B = booleanLattice 3;
i2 : posetJoin(B, "001", "100") o2 = {101} o2 : List
See also
joinExists
-- determines if the join exists for two elements of a poset
posetMeet
-- determines the meet for two elements of a poset
Ways to use
posetJoin
:
posetJoin(Poset,Thing,Thing)