/usr/include/mrpt/slam/ is in libmrpt-dev 1:1.5.5-1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/mrpt/slam/include/
/usr/include/mrpt/slam/include/mrpt/
/usr/include/mrpt/slam/include/mrpt/maps/
/usr/include/mrpt/slam/include/mrpt/maps/CMultiMetricMap.h
/usr/include/mrpt/slam/include/mrpt/maps/CMultiMetricMapPDF.h
/usr/include/mrpt/slam/include/mrpt/slam/
/usr/include/mrpt/slam/include/mrpt/slam.h
/usr/include/mrpt/slam/include/mrpt/slam/CGridMapAligner.h
/usr/include/mrpt/slam/include/mrpt/slam/CICP.h
/usr/include/mrpt/slam/include/mrpt/slam/CIncrementalMapPartitioner.h
/usr/include/mrpt/slam/include/mrpt/slam/CMetricMapBuilder.h
/usr/include/mrpt/slam/include/mrpt/slam/CMetricMapBuilderICP.h
/usr/include/mrpt/slam/include/mrpt/slam/CMetricMapBuilderRBPF.h
/usr/include/mrpt/slam/include/mrpt/slam/CMetricMapsAlignmentAlgorithm.h
/usr/include/mrpt/slam/include/mrpt/slam/CMonteCarloLocalization2D.h
/usr/include/mrpt/slam/include/mrpt/slam/CMonteCarloLocalization3D.h
/usr/include/mrpt/slam/include/mrpt/slam/CMultiMetricMap.h
/usr/include/mrpt/slam/include/mrpt/slam/CMultiMetricMapPDF.h
/usr/include/mrpt/slam/include/mrpt/slam/COccupancyGridMapFeatureExtractor.h
/usr/include/mrpt/slam/include/mrpt/slam/CRangeBearingKFSLAM.h
/usr/include/mrpt/slam/include/mrpt/slam/CRangeBearingKFSLAM2D.h
/usr/include/mrpt/slam/include/mrpt/slam/CRejectionSamplingRangeOnlyLocalization.h
/usr/include/mrpt/slam/include/mrpt/slam/PF_aux_structs.h
/usr/include/mrpt/slam/include/mrpt/slam/PF_implementations.h
/usr/include/mrpt/slam/include/mrpt/slam/PF_implementations_data.h
/usr/include/mrpt/slam/include/mrpt/slam/TKLDParams.h
/usr/include/mrpt/slam/include/mrpt/slam/TMonteCarloLocalizationParams.h
/usr/include/mrpt/slam/include/mrpt/slam/data_association.h
/usr/include/mrpt/slam/include/mrpt/slam/link_pragmas.h
/usr/include/mrpt/slam/include/mrpt/slam/observations_overlap.h