Rightwards Double Arrow

The Rightwards Double Arrow at U+21D2 is a symbol arrow that points to the right with two parallel strokes, most often read as “implies” or “therefore leads to.” It belongs to the Arrows block and functions as a visible mathematical and logical sign rather than ordinary punctuation. In formal logic, mathematics, and theoretical computer science, it commonly denotes implication: P ⇒ Q means that if P is true, then Q follows. In proofs and lecture notes, it is also used more informally for a consequence or next step, such as x > 0 ⇒ x² > 0. In technical writing, algorithms, and diagrams, the same mark can show transformation, conversion, or a directed relationship, especially where a stronger visual arrow is wanted than a single right arrow. It may appear in rewrite rules, state transitions, and explanatory notes such as “input ⇒ processed output.” A common lookalike is the double-lined arrow used in some contexts for entailment or implication, but conventions vary by field and author. For plain text meant for broad audiences, writers often replace it with words like “implies,” “leads to,” or “therefore” to avoid ambiguity.