Metaphosphoric acid - can it exist as monomer?

I read in my textbook that N2O5 can be prepared by reaction of HNO3 and P4O10 . A product HPO3 is also formed.


Then while discussing oxoacids of phosphorus , it said that metaphosphoric acid exists only in polymeric form.


So is there a contradiction ?




$\ce{HPO3}$ is an empirical formula for a material that is indeed polymerized. Phosphoric acid is actually [any of several acids containing phosphorus(V)](https://en.wikipedia.org/wiki/Phosphoric_acid); the formula $\ce{HPO3}$ represents a limiting case for long chains, or cycles containing a finite number (at least three) of $\ce{HPO3}$ units.


What is often called phosphoric acid, the monomer $\ce{H3PO4}$, is technically orthophosphoric acid.


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