U+2905 "⤅" Rightwards Two-Headed Arrow from Bar Unicode Character

U+2905 "⤅" Rightwards Two-Headed Arrow from Bar is a specialized arrow symbol included in the Unicode standard's Supplemental Arrows-B block, designed for use in mathematical logic and formal notation to represent a logical biconditional with a starting premise or constraint. Its visual design features a horizontal bar at the tail of the arrow, from which two arrowheads extend to the right, signifying a bidirectional relationship that originates from a defined initial condition or "bar." This notation is often employed in proofs, algorithm descriptions, or relational diagrams to indicate that a two-way implication is conditional upon the presence of the bar's associated element.