for n > 0 {
		if n < 17 {
			return FormatError("DHT has wrong length")
		}
		if err := d.readFull(d.tmp[:17]); err != nil {
			return err
		}
		tc := d.tmp[0] >> 4
		if tc > maxTc {
			return FormatError("bad Tc value")
		}
		th := d.tmp[0] & 0x0f
		// The baseline th <= 1 restriction is specified in table B.5.
		if th > maxTh || (d.baseline && th > 1) {
			return FormatError("bad Th value")
		}

			return nil, ErrNotFat
		} else {
			return nil, &FormatError{0, "invalid magic number", nil}
		}
	}
	offset := int64(4)

	// Read the number of FatArchHeaders that come after the fat_header.
	var narch uint32
	err = binary.Read(sr, binary.BigEndian, &narch)
	if err != nil {
		return nil, &FormatError{offset, "invalid fat_header", nil}
	}
	offset += 4

	if narch < 1 {

type Sym struct {
	Value uint64
	Type  rune
	Name  string
}

/*
 * Plan 9 a.out reader
 */

// formatError is returned by some operations if the data does
// not have the correct format for an object file.
type formatError struct {
	off int
	msg string
	val any
}

func (e *formatError) Error() string {
	msg := e.msg
	if e.val != nil {
		msg += fmt.Sprintf(" '%v'", e.val)
	}