One way is with a Polynomial class. For example, * `Poly:add(this, that)` returns the result of `this + that`. * `Poly:sub(this, that)` returns the result of `this - that`. * `Poly:mul(this, that)` returns the result of `this * that`. * `Poly:evaluate(this, evalmap)` returns the polynomial after replacing all free variables with constants as specified by `evalmap`. * `Poly:toList(this)` returns the polynomial in the correct output format. * `Solution::combine(left, right, symbol)` returns the result of applying the binary operator represented by `symbol` to `left` and `right`. * `Solution::make(expr)` makes a new `Poly` represented by either the constant or free variable specified by `expr`. * `Solution::parse(expr)` parses an expression into a new `Poly`.