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.
c is a nonnegative number (currently, must be an integer). Currently, b must be a positive integer in order to be well-defined. c=3 produces the normal/standard/simple logarithm; c=4 produces slog. In conventional English notation (not necessarily Lojbanic), this is the left-inverse of the same-order hyperoperator. See also: te'au'u, fe'au'u, dei'au'o.