Step 1: Identify the shared purpose and the distinctive image of each verse.
Step 2: Determine whether all the wording is rearranged or only part is taken.
Step 3: Identify the earlier version's merit: composition, clarity, concision or richness of thought.
Step 4: Give evidence of improvement or lost excellence in the new version.
Step 5: Test grammatical, lexical and temporal constraints in contested interpretations.
This distinguishes recognizing borrowing, comparing eloquence and testing coherence as separate analytical tasks.