In Pascal you can define functions inside other functions. So if, as is often the case, the file consists of one public function that calls a number of private

In Pascal you can define functions inside other functions. So if, as is often the case, the file consists of one public function that calls a number of private ones this can be enforced without needing to put them in separate files. In newer languages like C# you can do the same. Probably works in lots of other languages too, see Rosetta Code: Nested Function: https://rosettacode.org/wiki/Nested_function