w.fw = nil
	}
	return err
}

var flateReaderPool sync.Pool

func newFlateReader(r io.Reader) io.ReadCloser {
	fr, ok := flateReaderPool.Get().(io.ReadCloser)
	if ok {
		fr.(flate.Resetter).Reset(r, nil)
	} else {
		fr = flate.NewReader(r)
	}
	return &pooledFlateReader{fr: fr}
}

type pooledFlateReader struct {
	mu sync.Mutex // guards Close and Read
	fr io.ReadCloser
}

operations modulo m. // // The announced size of x must be smaller than or equal to that of m. func (x *Nat) ExpandFor(m *Modulus) *Nat { return x.expand(len(m.nat.limbs)) } // resetFor ensures out has the right size to work with operations modulo m. // // out is zeroed and may start at any size. func (out *Nat) resetFor(m *Modulus) *Nat { return out.reset(len(m.nat.limbs)) } // maybeSubtractModulus computes x -= m if and only if x >= m or if "always" is yes. // // It can be used to reduce modulo...