gistfile1.txt

scala> class Foo[A]
defined class Foo

scala> trait Monad[F[_]]; trait Catchable[F[_]]; trait Runner[F[_]]
warning: there were 3 feature warning(s); re-run with -feature for details
defined trait Monad
defined trait Catchable
defined trait Runner

scala> implicit def runner[F[_]](implicit M: Monad[F], C: Catchable[F]) = new Runner[F] {}
warning: there were 1 feature warning(s); re-run with -feature for details
runner: [F[_]](implicit M: Monad[F], implicit C: Catchable[F])Runner[F]

scala> implicitly[Runner[Foo]]
<console>:13: error: could not find implicit value for parameter e: Runner[Foo]
              implicitly[Runner[Foo]]
                        ^

scala> implicit val FooCatchable = new Catchable[Foo] {}
FooCatchable: Catchable[Foo] = $anon$1@6a41eaa2

scala> implicit val FooMonad = new Monad[Foo] {}
FooMonad: Monad[Foo] = $anon$1@335eadca

scala> implicitly[Runner[Foo]]
res1: Runner[Foo] = $anon$1@7d70d1b1