Question: Al-Battani and Ibn al-Shatir, have which mutual occupation?

Context paragraphs:
Ibn al-Shatir: Ibn al-Shatir or Ibn ash-Shatir (Arabic: ابن الشاطر‎ ‎ ; 1304–1375) was an Arab astronomer.  He worked as "muwaqqit" (موقت, religious timekeeper) in the Umayyad Mosque in Damascus and constructed a sundial for its minaret in 1371/72.

Siege of Constantinople (717–718): The Second Arab siege of Constantinople in 717–718 was a combined land and sea offensive by the Muslim Arabs of the Umayyad Caliphate against the capital city of the Byzantine Empire, Constantinople.  The campaign marked the culmination of twenty years of attacks and progressive Arab occupation of the Byzantine borderlands, while Byzantine strength was sapped by prolonged internal turmoil.  In 716, after years of preparations, the Arabs, led by Maslama ibn Abd al-Malik, invaded Byzantine Asia Minor.  The Arabs initially hoped to exploit Byzantine civil strife and made common cause with the general Leo III the Isaurian, who had risen up against Emperor Theodosius III.  Leo, however, tricked them and secured the Byzantine throne for himself.

Fragmentation (sociology): In urban sociology, fragmentation refers to the absence or the underdevelopment of connections between the society and the groupings of some members of that society on the lines of a common culture, nationality, race, language, occupation, religion, income level, or other common interests.  This gap between the concerned group and the rest might be social, indicating poor interrelationships among each other; economical based on structural inequalities; institutional in terms of formal and specific political, occupational, educative or associative organizations and/or geographic implying regional or residential concentration.  bell hooks coined the term when addressing the problem of 'hierarchy of oppression' within the feminist movement; where some felt experiencing more types of oppression gave greater validity to one's opinion and, therefore undermined group strength and solidarity within the movement as much as non-interscectional identity did in the 1970s [where female identity was seen predominantly through the lens of white, middle-class women and didn't take into consideration that identity could be made up of many more cultural influences such as race, gender, sexuality, spirituality etc. all intersecting across points of privilege and oppression].  hooks argued for greater inclusivity, mutual support and an understanding of various types of feminism within the movement; each sharing the same equity goals, yet having different ideas on the methods to achieve such goals.

Occupation of al-Ubulla (870): The Zanj occupation of al-Ubulla (Arabic: دخول الزنج الأبلة‎ ‎ ) was an event of the Zanj Rebellion, occurring on June 28, 870.  Zanj troops dispatched by their leader 'Ali ibn Muhammad advanced against the city of al-Ubulla on the Tigris and launched an attack against it.  Despite a defense set up by the Abbasid government to protect the city, it was successfully stormed and taken by the rebels.  Much of al-Ubulla was destroyed and many of its inhabitants were killed during the assault.

Al-Battani: Abū ʿAbd Allāh Muḥammad ibn Jābir ibn Sinān al-Raqqī al-Ḥarrānī aṣ-Ṣābiʾ al-Battānī (Arabic: محمد بن جابر بن سنان البتاني) (Latinized as Albategnius, Albategni or Albatenius) (c. 858 – 929) was an Arab astronomer, astrologer, and mathematician.  He introduced a number of trigonometric relations, and his "Kitāb az-Zīj" was frequently quoted by many medieval astronomers, including Copernicus.

Soviet occupation of the Baltic states (1940): The Soviet occupation of the Baltic states covers the period from the Soviet–Baltic mutual assistance pacts in 1939, to their invasion and annexation in 1940, to the mass deportations of 1941.

Dharma Karmadhipati yoga: Dharma Karmadhipati yoga arises when the lords of the 9th and the 10th bhavas counted from the " lagna " or the "Chandra-lagna" (the Moon-sign), whichever is stronger, establish a "sambandha" (mutual relationship) preferably in a kendra or a trikonasthana; it is a "shubha" (auspicious) " yoga ".  The 9th "bhava" (house) signifies "Poorvapunya", "Dharma" and "Bhagya", which are all auspicious significations.  The 10th house, also known as "Kirtisthana" and the "Rajyabhava", is the "Karmabhava" or the " Karmasthana ".  In general terms the 10th house refers to occupation, profession or means of livelihood, temporal honours, foreign travels, self-respect, knowledge and dignity.

Soviet–Lithuanian Mutual Assistance Treaty: The Soviet–Lithuanian Mutual Assistance Treaty (Lithuanian: "Lietuvos-Sovietų Sąjungos savitarpio pagalbos sutartis" ) was a bilateral treaty signed between the Soviet Union and Lithuania on October 10, 1939.  According to provisions outlined in the treaty, Lithuania would acquire about one fifth of the Vilnius Region, including Lithuania's historical capital, Vilnius, and in exchange would allow five Soviet military bases with 20,000 troops to be established across Lithuania.  In essence the treaty with Lithuania was very similar to the treaties that the Soviet Union signed with Estonia on September 28, and with Latvia on October 5.  According to official Soviet sources, the Soviet military was strengthening the defenses of a weak nation against possible attacks by Nazi Germany.  The treaty provided that Lithuania's sovereignty would not be affected.  However, in reality the treaty opened the door for the first Soviet occupation of Lithuania and was described by "The New York Times" as "virtual sacrifice of independence."

Supporting paragraphs: Al-Battani Ibn al-Shatir
Answer: astronomer