This dataset contains code to verify that the solution sets of certain systems of equations over finite algebras are equal to the relation \(\Delta^{(4)}_A\), which ensures that the clone of that algebra possesses a property called equational additivity. Moreover, we have added code that produces input files for the universal algebra calculator (uacalc), which simplifies the check of certain claims in our preprint ‘On when the union of two algebraic sets is algebraic’ (the final version of which can be found here).