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7.5.13.0. isUpperTriangular
Procedure from library ncpreim.lib (see ncpreim_lib).

Usage:
isUpperTriangular(M[,k]); M a matrix, k an optional int

Return:
int, 1 if the given matrix is upper triangular,
0 otherwise.

Note:
If k<>0 is given, it is checked whether M is strictly upper triangular.

Example:
 
LIB "ncpreim.lib";
ring r = 0,x,dp;
matrix M[2][3] =
0,1,2,
0,0,3;
isUpperTriangular(M);
==> 1
isUpperTriangular(M,1);
==> 1
M[2,2] = 4;
isUpperTriangular(M);
==> 1
isUpperTriangular(M,1);
==> 0