White Triangle Containing Small White Triangle

White Triangle Containing Small White Triangle at U+27C1 is a specialized mathematical symbol built from a hollow triangle with a smaller hollow triangle inside it. It is part of the Miscellaneous Mathematical Symbols-A block, a collection used for less common operators, relation signs, and diagrammatic notation. In real-world text it is uncommon and is mostly encountered in formal mathematics, logic, and theoretical computer science when an author or notation system needs a custom triangle-shaped operator. It may be defined locally in a paper, textbook, or specification for a relation between objects, a modal or proof-theoretic operator, or a diagram label; its meaning comes from that source rather than from a widely fixed convention. The symbol can also appear in symbol tables, font tests, and Unicode reference material where the goal is to show the available mathematical sign rather than to use it in ordinary prose. Because its shape is close to several other triangle operators, readers should rely on the surrounding definition, not just visual resemblance, when interpreting it.