This is very preliminary documentation.  These functions are about matrices
which define term orderings.  They expect and return matrices over RingZZ.
NewPositiveMat(M) -- returns a matrix with non-negative entries
  which  defines an equivalent term-ordering (but grading may
  be different!) 
NewMatMinimize(M) -- the (ordering) matrix obtained by removing
  linearly dependent rows 
NewDenseMatRevLex(n) -- produce the n-by-n dense matrix over
  RingZZ corresponding to the revlex ordering on n indets 
NewMatCompleteOrd(ConstMatrixView M) -- complete M to an
  ordering matrix; if M is suitable the resulting matrix defines a
  term-ordering.
NewMatCompleteOrd(ConstMatrixView M, ConstMatrixView NewRows) -- 
  concatenate M and NewRows, and remove redundant rows.
NewMatElim(NumIndets, IndetsToElim)  -- returns the dense matrix
  for the elimination ordering of the given indets 
NewMatElim(GradingM, IndetsToElim, IsHomog)  -- ??? 
NewHomogElimMat(GradingM, IndetsToElim)  -- ??? 
IsTermOrdering(M)    -- true iff matrix M defines a term ordering
IsPositiveGrading(M) -- true iff M defines a positive grading 
  (i.e. no null columns and first non-zero entry in each column is positive)
IsPositiveGrading(M, GradingDim)  -- true iff the first
  GradingDim rows of M define a positive grading 
Doc is woefully incomplete.
Definitely don't like the name NewMatMinimize!
Fixed 2009-09-22: Naming convention not respected ("Matrix" should be "Mat")