/usr/include/sbml/math/ is in libsbml5-dev 5.10.0+dfsg-1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/sbml/math/ASTBase.h
/usr/include/sbml/math/ASTBinaryFunctionNode.h
/usr/include/sbml/math/ASTCSymbol.h
/usr/include/sbml/math/ASTCSymbolAvogadroNode.h
/usr/include/sbml/math/ASTCSymbolDelayNode.h
/usr/include/sbml/math/ASTCSymbolTimeNode.h
/usr/include/sbml/math/ASTCiFunctionNode.h
/usr/include/sbml/math/ASTCiNumberNode.h
/usr/include/sbml/math/ASTCnBase.h
/usr/include/sbml/math/ASTCnExponentialNode.h
/usr/include/sbml/math/ASTCnIntegerNode.h
/usr/include/sbml/math/ASTCnRationalNode.h
/usr/include/sbml/math/ASTCnRealNode.h
/usr/include/sbml/math/ASTConstantNumberNode.h
/usr/include/sbml/math/ASTFunction.h
/usr/include/sbml/math/ASTFunctionBase.h
/usr/include/sbml/math/ASTLambdaFunctionNode.h
/usr/include/sbml/math/ASTNaryFunctionNode.h
/usr/include/sbml/math/ASTNode.h
/usr/include/sbml/math/ASTNumber.h
/usr/include/sbml/math/ASTPiecewiseFunctionNode.h
/usr/include/sbml/math/ASTQualifierNode.h
/usr/include/sbml/math/ASTSemanticsNode.h
/usr/include/sbml/math/ASTTypes.h
/usr/include/sbml/math/ASTUnaryFunctionNode.h
/usr/include/sbml/math/FormulaFormatter.h
/usr/include/sbml/math/FormulaParser.h
/usr/include/sbml/math/FormulaTokenizer.h
/usr/include/sbml/math/L3FormulaFormatter.h
/usr/include/sbml/math/L3Parser.h
/usr/include/sbml/math/L3ParserSettings.h
/usr/include/sbml/math/MathML.h