Let
\(\kappa\) be the signature that naturally generalizes the usual
signature on groups: it consists of the multiplication, and of
the \((\omega-1)\)-power. We denote by \(\sf DRG\) the
pseudovariety all finite semigroups whose regular \(\mathcal
R\)-classes are groups. Below, you can test whether two
\(\kappa\)-terms are equal over \(\sf DRG\).

The syntax is
the following: multiplication of terms \(s\) and \(t\) is
represented by "st", and the \((\omega-1)\)-power of a term
\(t\) by "t^w-1". Thus if, for instance, one of the
\(\kappa\)-terms you wish to test is
\((a(b^{\omega-1}a)^{\omega-1})^{\omega-1}b\), you should insert
"(a(b^w-1a)^w-1)^w-1b".