--Copyright The Numerical Algorithms Group Limited 1991.

)system touch /tmp/reado
)system chmod +r,-w /tmp/reado
)system touch /tmp/writo
)system chmod +w,-r /tmp/writo

nullo: FNAME := new("", "nullo", "x")
reado: FNAME := filename("/tmp", "reado", "")
writo: FNAME := "/tmp/writo"

[directory reado, name reado, extension reado]
[directory writo, name writo, extension writo]
[directory nullo, name nullo, extension nullo]

[exists? reado, readable? reado, writable? reado]
[exists? writo, readable? writo, writable? writo]
[exists? nullo, readable? nullo, writable? nullo]

)system rm -f /tmp/reado
)system rm -f /tmp/writo
