Firefox action by trigerring actions.

[ldarrambide]

up, down, left, right Spatial navigation. Most objects don't support it.
next, previous Next or previous sibling.
parent Parent.
first, last First or last child.
child Child x. To specify child object, append 1-based child index.

pa3fi => parentx3, ok
fi2 ???
No reference to "fi", sorry if did not understand well.