the relation of possible things to time and potency in al-Farabi's philosophy

Various meanings for possibility (general, particular and more special possibility) and future contingency _as a separate meaning_ mentioned by Ibn-Sina, havent any example in al-Farabi's works. In logical works of al-Farabi "possible" relates to time's junctures as well as its potency. This shows that possibility in his view has only one meaning and it is is identical to future contingency or dispositional possibility and therefor it is particular to material world. In some of his philosophical works he repeated this without stipulating the relation to Time. But in other works that attributed to al-Farabi _like Ibn-Sina's work_ possibility bases on "being caused" and "its dependency on other", therefor contains all other than God. In the first group of al-Farabies philosophical works "celestial bodies" have a critical situation. By definition they are necessary but having motion makes this assertion doubtful.