+/** Check whether expression is a polynomial. */
+bool ex::is_polynomial(const ex & vars) const
+{
+ if (is_a<lst>(vars)) {
+ const lst & varlst = ex_to<lst>(vars);
+ for (lst::const_iterator i=varlst.begin(); i!=varlst.end(); ++i)
+ if (!bp->is_polynomial(*i))
+ return false;
+ return true;
+ }
+ else
+ 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();
+ }
+}
+