Which statement properly distinguishes case form and predicate function?

A Second Sense of Majāz: Case Changes Through Ellipsis and Addition

• Because mithl is genitive, there can be no predicate
• Shayʾ is the predicate and kāf is the subject
• Kāf is a genitive noun and mithl a particle
• Mithl is genitive after kāf, and the phrase occupies the predicate position