In technical writing, I believe expressions like these do not require a definite article:

  • Function f(x) is such and such. Graph G has such property. Equation (10) combined with something else gives that.

I mean one should not (or need not?) say "the function f(x)", "the graph G", "the equation (10)", etc..

This is my recollection from what a copy editor did to my writing a long time ago. Is this impression correct? If so, what is the name of this rule? I mean how can I refer others to this point?

  • 1
    I think need not rather than should not. Sometimes, but not in every context, including the article can sound a little stilted. But other times it can be quite natural (even preferred). Circumstances alter cases, and all that. Mar 19, 2019 at 18:49
  • @FumbleFingers, thanks, interesting. In that case, the question would be what are the circumstances that make one more natural than the other.
    – passerby51
    Mar 20, 2019 at 18:29

1 Answer 1


That is my impression as well. As for the rule, it's because an article is not necessary before proper nouns. In your examples, Function f(x), Graph G, and Equation 10 are all proper nouns, having names f, G, and 10 respectively.

  • OK, this is a nice interpretation.
    – passerby51
    Mar 20, 2019 at 18:30

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.