\Lleftarrow
The \Lleftarrow command in LaTeX is used to produce a long double left arrow, often used in mathematical contexts to denote implications or transformations that are more visually emphasized than a standard left arrow.
Indicates that A is implied by B with emphasis.
A \Lleftarrow B
Represents a transformation from g(x) to f(x) with emphasis.
f(x) \Lleftarrow g(x)
Shows a sequence of implications or transformations with emphasis.
X \Lleftarrow Y \Lleftarrow Z