As part of a research team, comprising literary scholars and cognitive neuroscientists, studying theory of mind with fMRI, I was in charge of putting together a series of narrative vignettes containing different levels of what we called "mental embedment." To briefly illustrate our principle of counting levels of mental embedment, consider the following four examples: The sentence, "My last name begins with a Z, while Alan's last name begins with a P" contains no mental states, hence zero embedment.
In other words, if we are talking about underlying themes, evocations, and aphoristic truths, we are in at least the second level of embedment, for, to take in this vignette we have to become aware of the speaker's anticipation of a certain response on the part of the reader.
Researchers have carried out relevant experimental research on fracture conductivity of coal rock, in terms of proppant embedment
, crushing and wall compaction, and the damage of fracture fluid residue to fracture conductivity.