«إِنْ تَزَوَّجْتُكِ فَأَنْتِ طَالِقٌ»
“If I marry you, you are divorced.”
No marriage currently exists when the words are spoken. The Hanafi reasoning treats the condition as tied to the legal basis of the marriage relationship, so the effect of the suspended statement is considered upon the later marriage.
The Shafii reasoning evaluates a declaration made before the relationship exists differently, yielding a disagreement over the validity of the suspension.
The point is that future conditions cannot all be placed into one category. A condition linked to ownership, marriage or legal authority may differ from a condition involving a wholly unrelated external event.