Looks like a big circle `yi` with a bullet point `ho` inside designating covariant position of a focused parameter equipped with a small hook `xk` designating source Kleisli category and a big hook `xl` designating target Kleisli category.
Original mapping of derived functor definition:
This operator is available for functors with multiple parameters:
Type declaration with labels arrangement:
Available stretched versions (starting precedence is 6):