/usr/include/MAdLib/ is in libmadlib-dev 1.3.0-2.
This file is owned by root:root, with mode 0o755.
..
/usr/include/MAdLib/ANN.h
/usr/include/MAdLib/ANNperf.h
/usr/include/MAdLib/ANNx.h
/usr/include/MAdLib/AdaptInterface.h
/usr/include/MAdLib/AnalyticalSField.h
/usr/include/MAdLib/BackgroundSF.h
/usr/include/MAdLib/CallbackDefinition.h
/usr/include/MAdLib/CheckMesh.h
/usr/include/MAdLib/DiscreteSF.h
/usr/include/MAdLib/DistanceFunction.h
/usr/include/MAdLib/DistanceToPoints.h
/usr/include/MAdLib/LocalSizeField.h
/usr/include/MAdLib/MAdConfig.h
/usr/include/MAdLib/MAdLib.h
/usr/include/MAdLib/MAdOperations.h
/usr/include/MAdLib/MAdOutput.h
/usr/include/MAdLib/MeshDataBaseComm.h
/usr/include/MAdLib/MeshDataBaseCommPeriodic.h
/usr/include/MAdLib/MeshDataBaseInterface.h
/usr/include/MAdLib/MeshDataBaseParallelInterface.h
/usr/include/MAdLib/MobileObject.h
/usr/include/MAdLib/ModelInterface.h
/usr/include/MAdLib/PWLinearSField.h
/usr/include/MAdLib/SizeField.h
/usr/include/MAdLib/SizeFieldBase.h