type I2 interface {
	I1(int)     // method!
	I1[string]  // embedded I1
}

func _() {
	var x I2
	x.I1(0)
	x.m1("foo")
}

type I0 interface {
	m0()
}

type I3 interface {
	I0
	I1[bool]
	m(string)
}

func _() {
	var x I3
	x.m0()
	x.m1(true)
	x.m("foo")
}

type _ struct {
	( /* ERROR "cannot parenthesize" */ int8)

000002d0  04 00 80 41 24 c2 f9 e8  40 21 47 3c ab 8e 99 5e  |...A$...@!G<...^|
000002e0  0e 08 27 86 6c 29 ae 36  ed 21 18 23 67 cc f7 d5  |..'.l).6.!.#g...|
000002f0  3f e2 2c 48 2f 3d 47 e5  af d5 61 86 0f 91 69 30  |?.,H/=G...a...i0|
00000300  cf 84 56 f2 d3 c1 9a a3  a1 a2 c8 ef 4d 33 de 12  |..V.........M3..|
00000310  d6 46 55 5b c6 6a 65 a5  36 b5 51 5b db 04 25 aa  |.FU[.je.6.Q[..%.|

// arithmetic   domain     # trials      peak         rms
//    DEC       -10,+10      3000       6.5e-17     1.6e-17
//    IEEE      -10,+10     30000       9.2e-16     1.2e-16
// Also tested by ctan * ccot = 1 + i0.

// Cot returns the cotangent of x.
func Cot(x complex128) complex128 {
	d := math.Cosh(2*imag(x)) - math.Cos(2*real(x))
	if math.Abs(d) < 0.25 {
		d = tanSeries(x)
	}
	if d == 0 {
		return Inf()