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GB.GetRes
Syntax
GB.GetRes(M:IDEAL or MODULE):TAGGED("$gb.Res
")
Summary
returns the resolution computed so far
Description
This function returns the part of the resolution of M computed so
far. It does not compute the resolution of M as does
Res
, rather,
GB.GetRes
is intended primarily to be used within the Interactive
Groebner Framework. Thus, for example,
GB.GetRes
may be used to
examine the resolution as it is computed, one step at a time.
example
Use R ::= Q[txyz];
I := Ideal(x^2-yt,xy-zt,xy);
GB.Start_Res(I); -- start Interactive Groebner Framework
GB.Step(I); -- take one step in calculation of resolution
GB.GetRes(I); -- the resolution so far
0 --> R(-2)
-------------------------------
GB.Step(I); -- one more step
GB.GetResLen(I); -- the computed resolution still has length 1
1
-------------------------------
GB.GetBettiMatrix(I); -- the Betti Matrix so far
----
----
0
2
----
-------------------------------
GB.GetRes(I);
0 --> R^2(-2)
-------------------------------
GB.Steps(I,5); -- five more steps
GB.GetRes(I);
0 --> R(-4) --> R^3(-2)
-------------------------------
GB.Complete(I); -- complete the calculation
GB.GetResLen(I);
3
-------------------------------
GB.GetBettiMatrix(I);
--------------
--------------
0 0 0
0 0 3
0 0 0
0 4 0
2 0 0
--------------
-------------------------------
GB.GetRes(I);
0 --> R^2(-5) --> R^4(-4) --> R^3(-2)
-------------------------------
See Also