IUPAC naming for compounds containing carboxylic acid and anhydride together? According to IUPAC, the carboxylic acid comes first in priority order for functional groups, while anhydride has no prefix. Then how do you name a compound which contains both a carboxylic acid and an anhydride in it?
Acids are senior to anhydrides; therefore, a compound that contains both functional groups is named as acid.

The acid is substituted using the usual principles of substitutive nomenclature. The prefix ‘oxo’, denoting $\ce{=O}$, is used to indicate a carbonyl group when the group cannot be cited as suffix. The group $\ce{R-CO-O-{}}$ is indicated by an acyloxy prefix (e.g. ‘acetyloxy’, ‘propanoyloxy’, etc.).

For example: 3-(acetyloxy)-3-oxopropanoic acid

  

(Cyclic anhydrides, however, are named as heterocyclic pseudo ketones.)