What are the "retrogression" and "palace" in China's ancient buildings, are there any?

The concept of worship hall is closely related to I-shaped temple. I-shaped temples are made up of front and rear halls and worship halls. However, this layout was mainly popular in the Song and Yuan Dynasties, and there are not many examples now. Visit Ren Guang Palace in Beijing and Fucheng Temple in Suzhou. The following picture is from the Jin Dynasty's "Rebuilding Monument of the Zhongyue Temple in Daikin Cheng 'an", and the part between the last two halls is the worship hall.

I'm not sure about the word retrogression, but it should also be a layout technique. Judging from the content of Baidu search (I found a sentence on the Internet called Wuyuan ancient building "There is no retrogression between the wing and the main house"), it may be used to express a certain spatial relationship between the wing and the main house in quadrangle buildings.