IsNormalizing( lst, mat )
returns true or false according to whether the matrix mat leaves the
vectors in lst as a set invariant, i.e., Set(l * M) = Set( l )
.
gap> a := [ [ 1, 2 ], [ 3, 1 ] ];; gap> l := [ [ 1, 0 ], [ 0, 1 ], [ 1, 1 ], [ 0, 0 ] ];; gap> l * a; [ [ 1, 2 ], [ 3, 1 ], [ 4, 3 ], [ 0, 0 ] ] gap> IsNormalizing( l, a ); false
GAP 3.4.4