Initially, fears were limited to the likely rate of growth rather than the future of the underlying concept.

Some games give a different name to these types of matches, while still using the same underlying concept.

None of them changes the underlying concept of the function.

The underlying concept states that human construction and production of emissions, has created a number of gaseous chemical compounds which add to existing greenhouse gases.

In the 1990s it changed its name, and also the underlying concept behind the displays.