public void Determ()
{
var A = MathS.Matrix(new Entity[, ]
{
{ "A", "B" },
{ "C", "D" }
});
var v = TestExtensions.AsNotNull(A.Determinant)
.Substitute("A", 1)
.Substitute("B", 2)
.Substitute("C", 3)
.Substitute("D", 4);
Assert.Equal(-2, v.EvalNumerical());
}
