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GB.GetBettiMatrix
Syntax
GB.GetBettiMatrix(M:IDEAL or MODULE):TAGGED("$cocoa/io.Matrix")
Summary
returns the Betti matrix computed so far
Description
This function, if used after executing Res(M)
, prints the Betti
matrix for M. Within the Interactive Groebner Framework, in which
resolutions may be computed one step at a time, the function returns
the Betti matrix for the part of the resolution computed so far. See
GB.GetRes
for an example.
example
Use R ::= Q[t,x,y,z];
I := Ideal(x^2-yt,xy-zt,xy);
Res(I);
0 --> R^2(-5) --> R^4(-4) --> R^3(-2)
-------------------------------
GB.GetBettiMatrix(I);
--------------
--------------
0 0 0
0 0 3
0 0 0
0 4 0
2 0 0
--------------
-------------------------------
See Also