mekso binary operator: Lambert product-log W function; W(a, b)
Default: b=0. a can be any complex number (for which W is defined) and b is any integer denoting the branch (where b=0 implies the principal branch). See also: vau'au'o.
mekso ternary operator: positive super-logarithm; the super-logarithm (inverse operator of hyper-operator with respect to "height" of power tower) of a with base b and of order c-2.