\underleftarrow{AB}The command \underleftarrow{AB} is used in LaTeX to place a left-pointing arrow underneath a pair of characters or symbols, typically used to denote a transformation or mapping from one element to another in mathematical expressions.
A left-pointing arrow under the characters A and B, often used to indicate a mapping or transformation from B to A.
\underleftarrow{AB}Indicates that the transformation or mapping from Y to X results in Z.
\underleftarrow{XY} = ZA visual representation of a bidirectional transformation or relationship between f and g, with emphasis on the leftward direction.
f \underleftarrow{\rightarrow} g