Upper Left Corner with Dot

Upper Left Corner with Dot at U+27D4 is a specialized mathematical symbol that pairs an upper-left corner mark with an interior dot, typically for notation whose meaning is defined by the author. It is part of the Miscellaneous Mathematical Symbols-A block, a set of less common operators and relation signs used in advanced technical typesetting. In real mathematical writing, corner symbols are most familiar from delimiters, modal-logic notation, and formal systems that mark quoted expressions, syntactic objects, or semantic operators. The dotted variant is uncommon and usually appears only in papers or books that introduce it as a custom operator, for example to distinguish one corner-style construction from a related undotted one. It may also occur in symbol inventories, font test pages, Unicode charts, and software that exposes the full mathematical-symbol repertoire. Because it is rare in everyday mathematics, readers should not assume a universal meaning from the shape alone; the surrounding definition is what gives ⟔ its role in a formula.