/usr/include/feel/feelvf/ is in libfeel++-dev 1:0.95.0-final-2build2.
This file is owned by root:root, with mode 0o755.
..
/usr/include/feel/feelvf/bilinearform.hpp
/usr/include/feel/feelvf/bilinearformcontext.hpp
/usr/include/feel/feelvf/block.hpp
/usr/include/feel/feelvf/det.hpp
/usr/include/feel/feelvf/dummy.cpp
/usr/include/feel/feelvf/evaluator.hpp
/usr/include/feel/feelvf/expr.cpp
/usr/include/feel/feelvf/expr.hpp
/usr/include/feel/feelvf/exprbase.cpp
/usr/include/feel/feelvf/exprbase.hpp
/usr/include/feel/feelvf/eye.hpp
/usr/include/feel/feelvf/fec.hpp
/usr/include/feel/feelvf/form.hpp
/usr/include/feel/feelvf/formcontextbase.hpp
/usr/include/feel/feelvf/function.hpp
/usr/include/feel/feelvf/functordomain.cpp
/usr/include/feel/feelvf/functordomain.hpp
/usr/include/feel/feelvf/geometricdata.hpp
/usr/include/feel/feelvf/ginac.cpp
/usr/include/feel/feelvf/ginac.hpp
/usr/include/feel/feelvf/integrator.hpp
/usr/include/feel/feelvf/integratordirac.hpp
/usr/include/feel/feelvf/integratoron.hpp
/usr/include/feel/feelvf/inv.hpp
/usr/include/feel/feelvf/linearform.hpp
/usr/include/feel/feelvf/linearformcontext.hpp
/usr/include/feel/feelvf/matvec.hpp
/usr/include/feel/feelvf/norm.hpp
/usr/include/feel/feelvf/ones.hpp
/usr/include/feel/feelvf/operators.hpp
/usr/include/feel/feelvf/operators2.hpp
/usr/include/feel/feelvf/operators3.hpp
/usr/include/feel/feelvf/pattern.hpp
/usr/include/feel/feelvf/ppoperators.hpp
/usr/include/feel/feelvf/products.hpp
/usr/include/feel/feelvf/projectors.hpp
/usr/include/feel/feelvf/shape.hpp
/usr/include/feel/feelvf/stdmathfunctors.hpp
/usr/include/feel/feelvf/symm.hpp
/usr/include/feel/feelvf/test_fusion.cpp
/usr/include/feel/feelvf/trace.hpp
/usr/include/feel/feelvf/twovalued.hpp
/usr/include/feel/feelvf/unaryfunctor.cpp
/usr/include/feel/feelvf/unaryfunctor.hpp
/usr/include/feel/feelvf/val.hpp
/usr/include/feel/feelvf/vf.hpp