Richard O'Keefe wrote:
If you came across a sentence written using English syntax and closed-class words but Japanese open class words, would it still be English?
According to the theory that I have presented in http://www.naturalprogramming.com/to_read/estimating_understandability_etc.pdf such a sentence could be seen as containing a language of its own. That language would contain symbols (words) that might be found in Japanese and English dictionaries.
By that criterion, printf is definitely part of the C language.
In my earlier post I said that it has been said that the printf function does not belong to the C language. In the paper http://www.alcatel-lucent.com/bstj/vol57-1978/articles/bstj57-6-1991.pdf Ritchie et al. discuss the C language. They say on page 2015 (page 25 in the PDF file) that "The C language provides no facility for I/O.", and they continue discussing how things would be if the printf function would be built into the language. I understand this so that Ritchie et al. think that printf does not belong to the C language. Obviously these computer scientists think that only those textual symbols (keywords) that are built into the compiler belong to the programming language. As it seems to be so difficult to define what does or does not belong to a (programming) language, I thought that it might be useful to think that each computer program or any other document contains a language of its own. -- The Open University is incorporated by Royal Charter (RC 000391), an exempt charity in England & Wales and a charity registered in Scotland (SC 038302).