The financial sector no longer sees its main function as raising money for productive enterprise run by the middle classes.

Their main function now may be leisure, but devotees hope that modern engineering will make them relevant to transport once again.

Their main function, he once told me, should be to put their signatures on cheques.

Traditionally, food preparation was the main function of an island, so it would usually include a worktop area, a secondary sink and cabinetry.

And few would begrudge expenditure on helicopters and fast aircraft whose main function was to deliver medical aid in such circumstances.