/usr/include/polybori/iterators/ is in libbrial-dev 1.2.0-2.
This file is owned by root:root, with mode 0o755.
..
/usr/include/polybori/iterators/CBidirectTermIter.h
/usr/include/polybori/iterators/CCuddFirstIter.h
/usr/include/polybori/iterators/CCuddLastIter.h
/usr/include/polybori/iterators/CCuddNavigator.h
/usr/include/polybori/iterators/CExpIter.h
/usr/include/polybori/iterators/CGenericIter.h
/usr/include/polybori/iterators/COrderedIter.h
/usr/include/polybori/iterators/CStackSelector.h
/usr/include/polybori/iterators/CTermGenerator.h
/usr/include/polybori/iterators/CTermIter.h
/usr/include/polybori/iterators/CTermStack.h
/usr/include/polybori/iterators/CVariableIter.h
/usr/include/polybori/iterators/PBoRiOutIter.h
/usr/include/polybori/iterators/TransformedIterator.h