• Infix similarity operator. • xy is by default interpreted as CupCap[x,y]. • Used in mathematics for various notions of equivalence, usually fairly weak. • fg is often specifically used to indicate that f/g has bounded variation. • See also: \[NotCupCap] , \[Cap] , \[Cup] .
\[CupCap]
y is by default interpreted as CupCap[x, y]. 
g is often specifically used to indicate that f/g has bounded variation.