x y is by default interpreted as DoubleRightTee[x, y].
x y z groups as x (y z).
Used in mathematics to indicate various strong forms of logical implication—often tautological implication.
In prefix form, used to indicate a tautology.
See The Mathematica Book: Section 3.10.4 and Section 3.10.4.
See also: \[RightTee] , \[DoubleLeftTee] .