Veblen function

The Veblen function is a concept in set theory and mathematical logic, specifically in the study of ordinal numbers. It is named after the mathematician Oswald Veblen, who introduced it in the early 20th century. The Veblen function is primarily used to define large ordinal numbers and extends the ideas of transfinite recursion and ordinals. It provides a way to represent ordinals that exceed those that can be expressed by Cantor's ordinal numbers or through other standard means.