My friend (who is native German, we are both academics) wishes to include a sentence like this in his thesis:
"It is possible to design approximation algorithms which come conceivably close to exact algorithms."
The intended meaning here is that the algorithms of one type (approximation algorithms) are as close as one can imagine to the other type (exact algorithms).
My question is about the phrase "conceivably close". It did not sound right to me when reading the sentence, but my friend is quite convinced that such a formulation makes sense in English too. As an alternative, he would say the algorithms are "imaginably close" to each other.
Neither choice does sound correct to me, even the meaning eluded me at first, but I am not a native English speaker, either. Most of the time, I see the use with the adverb meaning a negative thing or a strange thing, things being "incredibly close" or "eerily close". I have used Google, but these phrases do come up -- interestingly, often by German authors or in English-language websites on Germany, but not exclusively so.
Can you help us figure out if the word choice is proper to use and the meaning comes across?