The term mufrad is used in grammatical and rhetorical analysis with attention to its level of description. In syntax, it may contrast a non-clausal expression with a complete clause; rhetoric also asks about causal linkage and reinforcement.
زَيْدٌ قَائِمٌ
Zayd is standing.
زَيْدٌ هُوَ قَائِمٌ
Zayd—he is standing.
The first uses «قائم» as a simple predicate. The second can be analyzed as a predicative structure involving «هو قائم», depending on the grammatical treatment of the pronoun. The fact that both contain «قائم» does not make their entire predicates identical.