👉 In mathematics, a sub-discoid is a type of closed surface or geometric object that can be defined as a three-dimensional shape with a single point of contact. A sub-discoid is typically characterized by its interior being a sphere and its exterior being a cylinder, which are both two-dimensional shapes. Sub-discoids arise naturally in various contexts such as in the study of surfaces with complex topology or in the analysis of mathematical structures that have a particular property. They can be geometrically defined using the concept