On shuffle of double zeta values over Fq[t]Fq[t]

We study relations between multizeta values for function fields in characteristic p   and give a combinatorial description of what is involved in the relations of double zeta values. The formulas for multizeta values with higher depths are more complicated. At the end of this paper we express ζ(r)ζ(s,t)ζ(r)ζ(s,t) as an FpFp-linear combinations of multizeta values.