«المشروطة الخاصة: وهي المشروطة العامة مع قيد اللادوام بحسب الذات»
The special conditional is the general conditional qualified by non-permanence with respect to the subject itself.
The general conditional asserts necessity while the subject bears its descriptive title. The special conditional adds that the predicate is not permanent throughout the entire existence of that subject.
“While the person is writing” and “not permanently” are therefore consistent: the first fixes the duration of the descriptive condition, the second denies lifelong persistence.