Thus, here is an example of a function: [{1, 1}, {2, 1}, {3, 2}] This function consists of three pairs, whose first members are 1, 2 and 3. It is customary to give functions names, like f, g or h, and if we call this function f, we generally use the following notation to describe it: f(1) = 1, f(2) = 1, f(3) = 2. The first members of the pairs are called arguments and the whole set of them is called the domain of the function. Thus the arguments of f here are 1, 2 and 3, and the set consisting of these three numbers is its domain.
Road speed limits are used in most countries to set the maximum (or minimum in some cases) speed at which road vehicles may legally travel on particular stretches of road. Speed limits may be variable and in some places speeds are unlimited (e.g. on some Autobahn sections in Germany).
The first maximum speed limit was the 10 mph (16 km/h) limit introduced in the United Kingdom in 1861. The highest posted speed limit in the world is 140 km/h (87 mph), which applies to some roads in Poland and Bulgaria; similarly Texas posts 85 mph (137 km/h) on one 40-mile (64 km) long toll road. However, some roads have no speed limit for certain classes of vehicles.