You've got to have some skills which means operators are trained and so on and so forth but you also have to understand things.

Having a watchful eye and knowing what to look for helps, but some manipulators are very good and they know what you will be looking for.

Some operators using the system weren't comfortable with computers and were happy with the old way of doing things.

Even in the latter case the line is only elliptical, a form of movement natural to the human body because of the joints, so this hardly demands any great skill from the operator.

The rational operator started a new era of opera cooperation in AD 2000.