}

func (c *concreteF[RCT, RG]) Fn() Fn[RCT] { // ERROR "not enough type arguments for type Fn: have 1, want 2"
	return c.makeFn()
}

func NewConcrete[RCT RC[RG], RG any](Rc RCT) F[RCT] { // ERROR "not enough type arguments for type F: have 1, want 2"
	return &concreteF[RCT]{ // ERROR "cannot use" "not enough type arguments for type concreteF: have 1, want 2"
		makeFn: nil,
	}

}

func (c *concreteF[RCT, RG]) Fn() Fn /* ERROR "not enough type arguments for type Fn: have 1, want 2" */ [RCT] {
	return c.makeFn()
}

func NewConcrete[RCT RC[RG], RG any](Rc RCT) F /* ERROR "not enough type arguments for type F: have 1, want 2" */ [RCT] {
	// TODO(rfindley): eliminate the duplicate error below.