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

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(New page: <command> <title>NC.IsFinite</title> <short_description> Check whether a <tt>K</tt>-algebra <tt>R/<M></tt> has finite <tt>K</tt>-dimension. </short_description> <syntax> NC.IsFinite(...)
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Revision as of 16:20, 2 October 2020


Check whether a K-algebra R/<M> has finite K-dimension.




Please note: The function(s) explained on this page is/are using the ApCoCoAServer. You will have to start the ApCoCoAServer in order to use it/them.

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 M: a LIST of words (or terms) in the defining ring. Note that each word is represented as a LIST, and that each element in the LIST involves only one indeterminate or none (a constant). For instance, the word x[2]y[1]x[2]^2 is represented as the LIST [x[2], y[1], x[2]^2].

  • @return: a BOOL value which is True if K-vector space R/<M> is finite and False otherwise.


Use ZZ/(2)[x[1..3]];
M:=[[x[3]^3], [x[1], x[2]], [x[2]^2], [x[1]^2], [x[2], x[3], x[1]], 
[x[1], x[3], x[1]], [x[1], x[3]^2], [x[2], x[3], x[2], x[3]], [x[1], 
x[3], x[2], x[3]]];

The output at the ApCoCoAServer is as follows. 
Found 2 cycles:
[3,2,1]  [2,1,3]  [1,3,2]  
[3,3,2]  [3,2,3]  [2,3,3]  
The group has polynomial growth of at most degree 2.

See also


Introduction to CoCoAServer