The Hausdorff series provides a solution to the equation
given by a recursive formula which can be expressed as nested commutators of
and
.
Evolutions of the Haussdorff series in various algebras and rings has been considered in obtaining a closed form of this formula. We consider the rectangular band
determined by the left zero semigroup
and the right zero semigroup
of order
and
, respectively. Let
be the semigroup ring spanned on ![]()
together with the identity element
. We provide a closed form of the formula for solving the equation in
.



