\[\Phi^{(2)}\left(a;b,b^{\prime};c,c^{\prime};q;x,y\right)=\sum_{m,n\geq 0}\frac%
{\left(a;q\right)_{m+n}\left(b;q\right)_{m}\left(b^{\prime};q\right)_{n}x^{m}y%
^{n}}{\left(q,c;q\right)_{m}\left(q,c^{\prime};q\right)_{n}},\]