Difference between revisions of "ApCoCoA-1:NC.IsHomog"

From ApCoCoAWiki
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</itemize>
 
</itemize>
 
<example>
 
<example>
NC.SetX(<quotes>xy</quotes>);  
+
USE QQ[x[1..2],y[1..2]];
F1 := [[1,<quotes>x</quotes>], [1,<quotes>y</quotes>]];
+
F1:= [[2x[1],y[1],x[2]^2], [-9y[2],x[1]^2,x[2]^3]]; -- 2x[1]y[1]x[2]^2-9y[2]x[1]^2x[2]^3
F2 := [[1,<quotes>xx</quotes>],[1,<quotes>xy</quotes>],[1,<quotes>x</quotes>]];  
+
F2:= [[2x[1],y[1],x[2]^2], [y[2],x[2]^3]]; -- 2x[1]y[1]x[2]^2+y[2]x[2]^3
F := [F1,F2];  
+
F3:= [[2x[1],y[1],x[2]]]; -- 2x[1]y[1]x[2]
NC.IsHomog(F);
+
NC.IsHomog(F1);
 +
NC.IsHomog(F2);
 +
NC.IsHomog(F3);
 +
NC.IsHomog([F1,F2,F3]);
 +
NC.IsHomog([F2,F3]);
 +
 
 
False
 
False
 
-------------------------------
 
-------------------------------
NC.IsHomog(F1);
 
 
True
 
True
 
-------------------------------
 
-------------------------------
NC.IsHomog(F2);
+
True
 +
-------------------------------
 
False
 
False
 +
-------------------------------
 +
True
 
-------------------------------
 
-------------------------------
 
</example>
 
</example>

Revision as of 17:10, 3 May 2013

NC.IsHomog

Check whether a polynomial or a LIST of polynomials is homogeneous in a non-commutative polynomial ring.

Syntax

NC.IsHomog(F:LIST):BOOL

Description

Please set non-commutative polynomial ring (via the command Use) before calling this function. For more information, please check the relevant commands and functions.

  • @param F: a non-commutative polynomial or a LIST of non-commutative polynomials. Each polynomial is represented as a LIST of LISTs, and each element in every inner LIST involves only one indeterminate or none (a constant). For example, the polynomial f=2x[2]y[1]x[2]^2-9y[2]x[1]^2x[2]^3+5 is represented as F:=[[2x[1],y[1],x[2]^2], [-9y[2],x[1]^2,x[2]^3], [5]]. The zero polynomial 0 is represented as the empty LIST [].

  • @return: a BOOL, which is True if F is homogeneous and False otherwise.

Example

USE QQ[x[1..2],y[1..2]];
F1:= [[2x[1],y[1],x[2]^2], [-9y[2],x[1]^2,x[2]^3]]; -- 2x[1]y[1]x[2]^2-9y[2]x[1]^2x[2]^3
F2:= [[2x[1],y[1],x[2]^2], [y[2],x[2]^3]]; -- 2x[1]y[1]x[2]^2+y[2]x[2]^3
F3:= [[2x[1],y[1],x[2]]]; -- 2x[1]y[1]x[2]
NC.IsHomog(F1);
NC.IsHomog(F2);
NC.IsHomog(F3);
NC.IsHomog([F1,F2,F3]);
NC.IsHomog([F2,F3]);

False
-------------------------------
True
-------------------------------
True
-------------------------------
False
-------------------------------
True
-------------------------------

See also

Use