davidhoyt

import algebra._, std.int._
import cats._, free._, Free._
import scala.language.implicitConversions

trait Expr[A]
case class Const[A](term: A) extends Expr[A]
case class Add[A](e1: Expr[A], e2: Expr[A])(implicit val r: Ring[A]) extends Expr[A]

type Exp[A] = FreeC[Expr, A]