Definition: In mathematics, an undiagram is a type of diagrammatic representation that is not intended to be fully or completely drawn out, but rather used for visualizing and understanding concepts. It is often used in the context of algebraic geometry, where it represents the relationships between curves or surfaces in projective space. An undiagram can be thought of as representing an abstract mathematical concept by drawing a diagram that shows how it relates to other concepts, without necessarily showing all details or working out all the
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