5.7.1 Testing whether an expression is a polynomial

Testing whether an expression is a polynomial in one or more variables can be done with the method

bool ex::is_polynomial(const ex & vars) const;

In the case of more than one variable, the variables are given as a list.

(x*y*sin(y)).is_polynomial(x)         // Returns true.
(x*y*sin(y)).is_polynomial(lst(x,y))  // Returns false.