/usr/share/doc/libjs-mathjax-doc/html/_sources/api/ is in libjs-mathjax-doc 2.7+20171212-1.
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/usr/share/doc/libjs-mathjax-doc/html/_sources/api/ajax.rst.txt
/usr/share/doc/libjs-mathjax-doc/html/_sources/api/callback.rst.txt
/usr/share/doc/libjs-mathjax-doc/html/_sources/api/elementjax.rst.txt
/usr/share/doc/libjs-mathjax-doc/html/_sources/api/html.rst.txt
/usr/share/doc/libjs-mathjax-doc/html/_sources/api/hub.rst.txt
/usr/share/doc/libjs-mathjax-doc/html/_sources/api/index.rst.txt
/usr/share/doc/libjs-mathjax-doc/html/_sources/api/inputjax.rst.txt
/usr/share/doc/libjs-mathjax-doc/html/_sources/api/jax.rst.txt
/usr/share/doc/libjs-mathjax-doc/html/_sources/api/localization.rst.txt
/usr/share/doc/libjs-mathjax-doc/html/_sources/api/message.rst.txt
/usr/share/doc/libjs-mathjax-doc/html/_sources/api/object.rst.txt
/usr/share/doc/libjs-mathjax-doc/html/_sources/api/outputjax.rst.txt
/usr/share/doc/libjs-mathjax-doc/html/_sources/api/queue.rst.txt
/usr/share/doc/libjs-mathjax-doc/html/_sources/api/signal.rst.txt
/usr/share/doc/libjs-mathjax-doc/html/_sources/api/variable.rst.txt