• Infix operator. • xy is by default interpreted as DoubleLeftTee[x,y]. • xyz groups as (xy)z. • Used in mathematics to indicate various strong forms of logical implication of x from y--often tautological implication. • See also: \[LeftTee] , \[DoubleRightTee] .
\[DoubleLeftTee]
y is by default interpreted as DoubleLeftTee[x, y]. 
y 
z groups as (x 
y) 
z. 