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isCM -- determines if a (hyper)graph is Cohen-Macaulay

Synopsis

Description

This uses the edge ideal notion of Cohen-Macaulayness; a hypergraph is called C-M if and only if its edge ideal is C-M.

i1 : R = QQ[a..e];
i2 : C = cycle R;
i3 : UnmixedTree = graph {a*b, b*c, c*d};
i4 : MixedTree = graph {a*b, a*c, a*d};
i5 : isCM C

o5 = true
i6 : isCM UnmixedTree

o6 = true
i7 : isCM MixedTree

o7 = false

See also

Ways to use isCM :

For the programmer

The object isCM is a method function.