Not all phonologists agree that syllables have internal structure; in fact, some phonologists doubt the existence of the syllable as a theoretical entity.

Black holes, which at the time I wrote "Killing Vector" were purely theoretical entities, form a standard part of modern cosmology.

If fusion centers were a theoretical entity slated to begin operating in a year or two, this might be adequate.

Obviously, if production prices are regarded only as purely "theoretical" entities, then it is not possible to claim also that they really regulate actual prices.

Editorial: the Higgs boson is a theoretical entity of the kind that scientists like to call non-trivial.

This is a theoretical entity that contains a specification of the word's defining characteristics.

I've seen many documentaries and articles that seem to discuss "dark matter" as a matter of fact rather than a theoretical, yet-to-be-proved entity.

Understood this way, truth conditions are theoretical entities.

This paper also argued that the idea of a luminiferous aether-one of the leading theoretical entities in physics at the time-was superfluous.

Earlier in this chapter, we distinguished between the syndrome as a theoretical entity and the syndrome as a clinical observation.