Patches by Vladimir.

[ginac.git] / ginac / ex.cpp

diff --git a/ginac/ex.cpp b/ginac/ex.cpp
index f1835377d2fbd9b6e0e83c289feea3c8361e36ef..d0645eef7f99f6421c58d71e91b39cfb367473f5 100644 (file)
--- a/ginac/ex.cpp
+++ b/ginac/ex.cpp
@@ -28,6 +28,7 @@
 #include "mul.h"
 #include "ncmul.h"
 #include "numeric.h"
+#include "matrix.h"
 #include "power.h"
 #include "lst.h"
 #include "relational.h"
@@ -254,6 +255,17 @@ bool ex::is_polynomial(const ex & vars) const
                return bp->is_polynomial(vars);
 }
 
+/** Check whether expression is zero or zero matrix. */
+bool ex::is_zero_matrix() const
+{
+       if (is_zero())
+               return  true;
+       else {
+               ex e = evalm();
+               return is_a<matrix>(e) && ex_to<matrix>(e).is_zero_matrix();
+       }
+}
+
 // private
 
 /** Make this ex writable (if more than one ex handle the same basic) by