syntax.Xor: token.XOR,

	syntax.Mul:    token.MUL,
	syntax.Div:    token.QUO,
	syntax.Rem:    token.REM,
	syntax.And:    token.AND,
	syntax.AndNot: token.AND_NOT,
	syntax.Shl:    token.SHL,
	syntax.Shr:    token.SHR,

}

// This is only used for operations that may cause overflow.
var op2str2 = [...]string{
	token.ADD: "addition",
	token.SUB: "subtraction",
	token.XOR: "bitwise XOR",
	token.MUL: "multiplication",
	token.SHL: "shift",
}

// If typ is a type parameter, underIs returns the result of typ.underIs(f).
// Otherwise, underIs returns the result of f(under(typ)).
func underIs(typ Type, f func(Type) bool) bool {
	typ = Unalias(typ)

			}
		}
	}
}

func BenchmarkModInverse(b *testing.B) {
	p := new(Int).SetInt64(1) // Mersenne prime 2**1279 -1
	p.abs = p.abs.shl(p.abs, 1279)
	p.Sub(p, intOne)
	x := new(Int).Sub(p, intOne)
	z := new(Int)
	for i := 0; i < b.N; i++ {
		z.ModInverse(x, p)
	}
}

// testModSqrt is a helper for TestModSqrt,

	default:
		// Otherwise, use Tonelli-Shanks.
		return z.modSqrtTonelliShanks(x, p)
	}
}

// Lsh sets z = x << n and returns z.
func (z *Int) Lsh(x *Int, n uint) *Int {
	z.abs = z.abs.shl(x.abs, n)
	z.neg = x.neg
	return z
}

// Rsh sets z = x >> n and returns z.
func (z *Int) Rsh(x *Int, n uint) *Int {
	if x.neg {
		// (-x) >> s == ^(x-1) >> s == ^((x-1) >> s) == -(((x-1) >> s) + 1)

		{"RBRACE", Const, 0},
		{"RBRACK", Const, 0},
		{"REM", Const, 0},
		{"REM_ASSIGN", Const, 0},
		{"RETURN", Const, 0},
		{"RPAREN", Const, 0},
		{"SELECT", Const, 0},
		{"SEMICOLON", Const, 0},
		{"SHL", Const, 0},
		{"SHL_ASSIGN", Const, 0},
		{"SHR", Const, 0},
		{"SHR_ASSIGN", Const, 0},
		{"STRING", Const, 0},
		{"STRUCT", Const, 0},
		{"SUB", Const, 0},
		{"SUB_ASSIGN", Const, 0},