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checks if a facet complex is a
tree
IsTree5(L: LIST): [BOOL,LIST ]
IsTree5(L: LIST, "NOOPT"): [BOOL,LIST]
IsTree5(L: LIST, "OPT"): [BOOL,LIST]
IsTree5(L: LIST, "CS_NOOPT"): [BOOL,LIST]
IsTree5(L: LIST, "CS_OPT"): [BOOL,LIST]
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This function return whether the facet complex described by the
list L of square free power products is a tree, plus a list which:
- is empty if L is a tree
- contains three elements of a cycle of L if L is not a tree.
Four options
NOOPT
,
OPT
,
CS_NOOPT
,
CS_OPT
are available as second
argument, specifying different algorithms; the default is
CS_OPT
.
For a full description of the algorithms we refer to the paper
M. Caboara, S. Faridi e P. Selinger, Simplicial cycles and the computation
of symplicial trees. Accepted for publication on the Journal of Symbolic
Computation (2006).
Use R ::= Q[x,y,z,t];
D := [xy, yz, zt, tx];
IsTree5(D);
[FALSE, [xy, xt, yt]]
-------------------------------
IsTree5([xy, yz, zt]);
[TRUE, [ ]]
-------------------------------
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