The phrase "if such exist" is correct and usable in written English.
It is a way of expressing doubt or uncertainty as to the existence of something. For example: "We have searched extensively for other sites of the same antiquity but have found none - if such exist."
Since spontaneous diffusion of RFP did not occur in non-infected, RFP-transfected (not shown) and, most importantly, in rA75/17red Hko/Hcomp-infected canine brain cell cultures, pre-existing channels between normal astrocytes, if such exist at all, are presumably not employed for nucleocapsid transfer from one cell to another.
Chemical studies on still-heavier elements await the discovery of longer-lived isotopes (if such exist and can be synthesized).
To the Editor: The president can resolve the issue of the missing Iraqi explosives by ordering the Pentagon to release satellite photographs of Al Qaqaa complex, if such exist, during the times the materials were believed to have been removed.
The president can resolve the issue of the missing Iraqi explosives by ordering the Pentagon to release satellite photographs of Al Qaqaa complex, if such exist, during the times the materials were believed to have been removed.
Thoughtful finance ministers, if such exist, should wonder whether their successors' budgets will stand the strain.The puzzling medical aspect of Alzheimer's is that no one truly knows how it debilitates and kills.
Moreover, substances quite generally do not depend for their identity upon their (accidental) particularized properties, if such exist, nor upon the events in which they participate, nor upon the places they occupy, nor upon other substances.
If I could change one law, it would be the one that permits halal slaughter, if such exists.
But who at Justice advised what person at the White House that Rich should be pardoned, and how were "those comments," if such existed, transmitted to Clinton?
A tactful program insert inveighed gently against audience noisemakers, but the disruptive cough, if such existed, never had a chance against what was coming from the stage.
This spiritual teaching echoes generations of martyrs who relied on God as their support, resisting the temptation of power, if such existed.
"Deep down," Andrew admits, "at the bottom of my soul, if such exists, I am finally unmoved by what I've done".
