A Kiss 4-differences term from a ternary term (Q5950787)

It was shown by E. W. Kiss that every modular variety has a 4-difference term, i.e. a 4-ary term \(q\) satisfying \(q(x,y,x,y)=x\), \(q(x,x,y,y)=y\) and \(q(x,y,z,v)[\beta ,\alpha ]q(x,y,w,v)\) whenever \(\alpha ,\beta \in \text{Con } A\), \(\langle x,y\rangle \in \alpha \), \(\langle z,v\rangle \in \alpha \), \(\langle x,z\rangle \in \beta \), \(\langle y,v\rangle \in \beta \) and \(\langle z,w\rangle \in \alpha \beta \) where \([\beta ,\alpha ]\) denotes the commutator of congruences \(\alpha , \beta \). It is a question how to construct \(q\) by using of the Day's terms. The author finds an extremely simple way how to construct \(q\) by means of the so-called difference term, which is a ternary term \(t\) satisfying \(t(x,y,y)=x\) and \(t(x,x,y)[\alpha ,\alpha ]y\) for every \(\alpha \in \text{Con } A\) and \(\langle x,y\rangle \in \alpha \).