This grammar rule is using the exclusive form.

Exclusive form of grammar is used to refer to a specific object only.

He is the type of person who thinks it's a moonlit night if it's bright, so he only has a one-sided perspective.

He thought deeply and said, 'I think, therefore I am.'

The characteristic of annelids is that their bodies are divided into ring-shaped segments.

This butterfly valve is used to control the flow of fluid.

He explained in detail about the structure of the sphenoid bone.

He drew a straight line using a T-square.

She is learning the grammar of the present progressive form.

The legend of Yamata no Orochi is deeply rooted in Japanese mythology.