Chiastic structure
(重定向自Palistrophe)

Chiastic structure, or chiastic pattern, is a literary technique in narrative motifs and other textual passages. An example of chiastic structure would be two ideas, A and B, together with variants A' and B', being presented as A,B,B',A'. Alternative names include ring structure, because the opening and closing 'A' can be viewed as completing a circle, palistrophe, or symmetric structure. It may be regarded as chiasmus scaled up from clauses to larger units of text.