/usr/ is in libqalculate-dev 0.9.10-1.
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..
/usr/lib/x86_64-linux-gnu/
/usr/include/
/usr/include/libqalculate/
/usr/include/libqalculate/BuiltinFunctions.h
/usr/include/libqalculate/Calculator.h
/usr/include/libqalculate/DataSet.h
/usr/include/libqalculate/ExpressionItem.h
/usr/include/libqalculate/Function.h
/usr/include/libqalculate/MathStructure.h
/usr/include/libqalculate/Number.h
/usr/include/libqalculate/Prefix.h
/usr/include/libqalculate/Unit.h
/usr/include/libqalculate/Variable.h
/usr/include/libqalculate/includes.h
/usr/include/libqalculate/qalculate.h
/usr/include/libqalculate/util.h
/usr/lib/
/usr/lib/x86_64-linux-gnu/libqalculate.a
/usr/lib/x86_64-linux-gnu/pkgconfig/
/usr/lib/x86_64-linux-gnu/pkgconfig/libqalculate.pc
/usr/share/
/usr/share/doc/
/usr/share/doc/libqalculate-dev/
/usr/share/doc/libqalculate-dev/copyright
/usr/lib/x86_64-linux-gnu/libqalculate.so
/usr/share/doc/libqalculate-dev/changelog.Debian.gz