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Ord
Syntax
Ord():MAT
Ord(R:RING):MAT
Ord(M:MAT):MAT
Summary
matrix defining a term-ordering
Description
The first two forms return matrices which describe the term-ordering
of the current ring or of the ring R, respectively.  The last form is
used as a modifier when creating a new ring.  In that case, it
determines the term-ordering for the ring (see 'Orderings').  Its
argument is a matrix of small integers which defines a term-ordering;
i.e. for a ring with N indeterminates it must be an NxN matrix of full
rank where the first non-zero entry in each column is positive.  The
matrix entries must be in the range -32767 to +32767, otherwise an
error results.

Example

Use S ::= Q[x,y,z], Ord(Mat([[1,0,0],
                             [0,1,0],
                             [0,0,1]]));

M := Mat([[1,1],[0,-1]]);
T ::= Q[a,b], Ord(M);
U ::= Z/(101)[x,y,z,t], DegRevLex;
-- The term-order for the current ring, S.
Ord();
Mat[
  [1, 0, 0],
  [0, 1, 0],
  [0, 0, 1]
]
-------------------------------
Ord(T);
Mat[
  [1, 1],
  [0, -1]
]
-------------------------------
Ord(U);
Mat[
  [1, 1, 1, 1],
  [0, 0, 0, -1],
  [0, 0, -1, 0],
  [0, -1, 0, 0]
]
-------------------------------
See also: