One of the well-known Models by OpenAI using Chain of Thought techniques.
"We are introducing OpenAI o1, a new large language model trained with reinforcement learning to perform complex reasoning. o1 thinks before it answers—it can produce a long internal chain of thought before responding to the user." [e2e35a]

o1

o3

2025, Feb 01. I just tried o3 mini The Prime Time, YouTube

Footnotes


[e2e35a] 2024, Sep 12. [Learning to reason with LLMs](# Learning to reason with LLMs). OpenAI Blog.