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).
In the mid-1970s, however, Congress established a national maximum speed limit by withholding highway funds from states that maintained speed limits greater than 55 mph. The requirement was loosened for rural interstates in 1987 and completely repealed in 1995.