Identity functors are used to map each object to itself and each morphism to itself.

I have many idea hamsters running around in my head.

I have many idea futures that I want to explore.

Principal ideal rings are an important concept in abstract algebra.

Principal ideal domains are integral domains in which every ideal is principal.

Transcendental idealisms are philosophical concepts that explore the relationship between knowledge and experience.

Cultural identity plays a significant role in shaping an individual's beliefs and values.

He steals someone's identity.

He has stolen someone's identity.

He stole someone's identity and used it to open credit cards in their name.