Separating arguments of a function
In English, a comma normally separates components of a bracketed list, such as the arguments of a function.
For example, \(f(x,y)\) is the application of a function \(f\) to two arguments, \(x\) and \(y\).
When the convention for number notation is to use a comma as the decimal separator, this can lead to an ambiguity when the arguments are numbers.
For example, is \(f(1,2)\) the application of a function of one argument, or two?
Instead, a common convention is to use a semicolon as the item separator.
For example, \(f(1;2)\) is unambiguously a function of two arguments.
Others use spacing to separate items, in addition to a comma, such as \(f(1,\, 2)\). (but Space is significant!)