The textbook’s inference contains three key terms:
World: what the conclusion is about.
Originated: what is asserted in the conclusion.
Changing: the mediating term that links the premises.
In general form: if something falls under B, and everything under B has property C, then that thing has property C. The exact quantification of the source’s first premise depends on how “the world” is understood as its subject.
The essential point is that the middle or mediating term connects the subject and predicate of the conclusion. Merely memorizing three lines is not the understanding of nazar.