panic("unreachable")
				}
				var errnan bool // set if execution of f panicked with ErrNaN
				// protect execution of f
				func() {
					defer func() {
						if p := recover(); p != nil {
							_ = p.(ErrNaN) // re-panic if not ErrNaN
							errnan = true
						}
					}()
					f(got, xx, yy)
				}()
				if math.IsNaN(z) {
					if !errnan {

	prec uint32
	mode RoundingMode
	acc  Accuracy
	form form
	neg  bool
	mant nat
	exp  int32
}

// An ErrNaN panic is raised by a [Float] operation that would lead to
// a NaN under IEEE 754 rules. An ErrNaN implements the error interface.
type ErrNaN struct {
	msg string
}

func (err ErrNaN) Error() string {
	return err.msg
}

// NewFloat allocates and returns a new [Float] set to x,

// case.
func (z *Float) Sqrt(x *Float) *Float {
	if debugFloat {
		x.validate()
	}

	if z.prec == 0 {
		z.prec = x.prec
	}

	if x.Sign() == -1 {
		// following IEEE754-2008 (section 7.2)
		panic(ErrNaN{"square root of negative operand"})
	}

	// handle ±0 and +∞
	if x.form != finite {
		z.acc = Exact
		z.form = x.form
		z.neg = x.neg // IEEE754-2008 requires √±0 = ±0
		return z
	}

pkg math/big, method (*Int) ModSqrt(*Int, *Int) *Int
pkg math/big, method (Accuracy) String() string
pkg math/big, method (ErrNaN) Error() string
pkg math/big, method (RoundingMode) String() string
pkg math/big, type Accuracy int8
pkg math/big, type ErrNaN struct
pkg math/big, type Float struct
pkg math/big, type RoundingMode uint8
pkg mime, const BEncoding = 98
pkg mime, const BEncoding WordEncoder

		{"(*Rat).Sub", Method, 0},
		{"(*Rat).UnmarshalText", Method, 3},
		{"(Accuracy).String", Method, 5},
		{"(ErrNaN).Error", Method, 5},
		{"(RoundingMode).String", Method, 5},
		{"Above", Const, 5},
		{"Accuracy", Type, 5},
		{"AwayFromZero", Const, 5},
		{"Below", Const, 5},
		{"ErrNaN", Type, 5},
		{"Exact", Const, 5},
		{"Float", Type, 5},
		{"Int", Type, 0},
		{"Jacobi", Func, 5},