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4.8.6 Orderings

Polynomials are always sorted with respect to the ordering of their base ring. All the operations involving polynomials utilize and preserve this ordering. The user can define custom orderings or choose a predefined term-ordering. Some commands temporarily change the term-ordering in order to make a computation. The various possibilities are discussed more fully, below.

The command Ord can be used both as a modifier to set the ordering of the ring and as a way to view the matrix defining the current term-ordering.

Example

Use R ::= QQ[x,y,z], Lex; -- lexicographic term-ordering (predefined) Use S ::= QQ[u,v], Ord([[1,1],[2,-3]]); -- custom term-ordering Ord(R); -- the matrix defining the term-ordering for R Mat([ [1, 0, 0], [0, 1, 0], [0, 0, 1] ]) ------------------------------- Ord(S); -- the matrix defining the term-ordering for S Mat([ [1, 1], [2, -3] ]) -------------------------------