Infix arrow operator.
x y is by default interpreted as DoubleRightArrow[x, y].
Used in mathematics to indicate various strong forms of convergence.
Also used to indicate algebraic field extensions.
Not the same as \[Implies].
See The Mathematica Book: Section 3.10.1 and Section 3.10.4.
See also: \[DoubleLongRightArrow] , \[RightArrow] , \[DoubleLeftArrow] .