/usr/include/klftools/ is in libklatexformula3-dev 3.3.0~beta-1.
This file is owned by root:root, with mode 0o755.
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/usr/include/klftools/klfadvancedconfigeditor.h
/usr/include/klftools/klfcolorchooser.h
/usr/include/klftools/klfconfigbase.h
/usr/include/klftools/klfdatautil.h
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/usr/include/klftools/klfflowlayout.h
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/usr/include/klftools/klfitemviewsearchtarget.h
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/usr/include/klftools/klflatexedit.h
/usr/include/klftools/klfpathchooser.h
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/usr/include/klftools/klfutil.h
/usr/include/klftools/qtcolortriangle.h