حصن منبع تلاشت فوق صخرتها اعراب جملة تلاشت

The content describes a fort that disappeared on top of its rocky formation, and it was inhabited by a group of Arab nomads. The word “تلاش” is a past tense verb and it is decline according to the rules of “فتح”. The letter “تاء” in “تلاش” is a feminine letter but it has no grammatical position in the sentence. The sentence is in the place of nominative predicate.