Mutabi‘: a transmitter who supplies a parallel supporting route.
Complete mutaba‘ah: agreement at the same immediate teacher.
Partial mutaba‘ah: agreement reached at a higher link or the same Companion by another route.
Shahid: a related report from a different Companion, with verbal or semantic likeness.
I‘tibar: the method of tracing and comparing paths, not a third independent type of report.
These tools clarify how acceptable reports can relate to one another. When two accepted reports seem apparently contradictory, the next question is whether their meanings can be reconciled or whether other principles of preference must be applied. This opens the discussion of muhkam and mukhtalif al-hadith.