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SAGBI, SAGBIHomog    --    SAGBI bases for subalgebra


Syntax 
sagbi(L: LIST): LIST
SAGBI(L: LIST): LIST
SAGBIHomog(L: LIST): LIST
SAGBIHomog(L: LIST, TruncDeg: INT): LIST

Description
These functions return a SAGBI (Subalgebra Analogue of GBases for Ideals) of the algebra generated by L.

NOTE: a SAGBI might be infinite, so (interrupt the computation and) use truncation if the computation takes too long.

Verbosity range 40-90.

Example 
/**/ use P ::= QQ[x,y,z];
/**/ G := [x^2,  x*y -z^2,  y^2];
/**/ sagbi(G);
[y^2,  x*y -z^2,  x^2,  x*y*z^2 +(-1/2)*z^4]

/**/ SetVerbosityLevel(50);
/**/ SAGBIHomog(G, 3);    -- Truncation: up to degree 3
 (... verbosity ...)
[y^2,  x*y -z^2,  x^2]

See Also