/usr/include/shogun/mathematics/linalg/ is in libshogun-dev 3.2.0-7.5.
This file is owned by root:root, with mode 0o755.
..
/usr/include/shogun/mathematics/linalg/eigsolver/
/usr/include/shogun/mathematics/linalg/eigsolver/DirectEigenSolver.h
/usr/include/shogun/mathematics/linalg/eigsolver/EigenSolver.h
/usr/include/shogun/mathematics/linalg/eigsolver/LanczosEigenSolver.h
/usr/include/shogun/mathematics/linalg/linop/
/usr/include/shogun/mathematics/linalg/linop/DenseMatrixOperator.h
/usr/include/shogun/mathematics/linalg/linop/LinearOperator.h
/usr/include/shogun/mathematics/linalg/linop/MatrixOperator.h
/usr/include/shogun/mathematics/linalg/linop/SparseMatrixOperator.h
/usr/include/shogun/mathematics/linalg/linsolver/
/usr/include/shogun/mathematics/linalg/linsolver/CGMShiftedFamilySolver.h
/usr/include/shogun/mathematics/linalg/linsolver/ConjugateGradientSolver.h
/usr/include/shogun/mathematics/linalg/linsolver/ConjugateOrthogonalCGSolver.h
/usr/include/shogun/mathematics/linalg/linsolver/DirectLinearSolverComplex.h
/usr/include/shogun/mathematics/linalg/linsolver/DirectSparseLinearSolver.h
/usr/include/shogun/mathematics/linalg/linsolver/IterativeLinearSolver.h
/usr/include/shogun/mathematics/linalg/linsolver/IterativeShiftedLinearFamilySolver.h
/usr/include/shogun/mathematics/linalg/linsolver/IterativeSolverIterator.h
/usr/include/shogun/mathematics/linalg/linsolver/LinearSolver.h
/usr/include/shogun/mathematics/linalg/ratapprox/
/usr/include/shogun/mathematics/linalg/ratapprox/logdet/
/usr/include/shogun/mathematics/linalg/ratapprox/logdet/LogDetEstimator.h
/usr/include/shogun/mathematics/linalg/ratapprox/logdet/computation/
/usr/include/shogun/mathematics/linalg/ratapprox/logdet/computation/aggregator/
/usr/include/shogun/mathematics/linalg/ratapprox/logdet/computation/aggregator/IndividualJobResultAggregator.h
/usr/include/shogun/mathematics/linalg/ratapprox/logdet/computation/job/
/usr/include/shogun/mathematics/linalg/ratapprox/logdet/computation/job/DenseExactLogJob.h
/usr/include/shogun/mathematics/linalg/ratapprox/logdet/computation/job/RationalApproximationCGMJob.h
/usr/include/shogun/mathematics/linalg/ratapprox/logdet/computation/job/RationalApproximationIndividualJob.h
/usr/include/shogun/mathematics/linalg/ratapprox/logdet/opfunc/
/usr/include/shogun/mathematics/linalg/ratapprox/logdet/opfunc/DenseMatrixExactLog.h
/usr/include/shogun/mathematics/linalg/ratapprox/logdet/opfunc/LogRationalApproximationCGM.h
/usr/include/shogun/mathematics/linalg/ratapprox/logdet/opfunc/LogRationalApproximationIndividual.h
/usr/include/shogun/mathematics/linalg/ratapprox/opfunc/
/usr/include/shogun/mathematics/linalg/ratapprox/opfunc/OperatorFunction.h
/usr/include/shogun/mathematics/linalg/ratapprox/opfunc/RationalApproximation.h
/usr/include/shogun/mathematics/linalg/ratapprox/tracesampler/
/usr/include/shogun/mathematics/linalg/ratapprox/tracesampler/NormalSampler.h
/usr/include/shogun/mathematics/linalg/ratapprox/tracesampler/ProbingSampler.h
/usr/include/shogun/mathematics/linalg/ratapprox/tracesampler/TraceSampler.h