**System for the Right-Hand Product**

Let us multiply the by . To do so, we prepare two systems of recurrence equations, one for each factor.

The following system describes , which is independent from .

`> `
**sys1:={h(n+1,k)-h(n,k)} union eval(subs(h=proc(k) h(n,k) end,subs(n=k,sys)));**

We next obtain a system that describes , the weight to multiply with:

`> `

`> `

`> `

`> `
**sys2:=collect(map(numer,{"","}),h);**

We finally perform the product by a call to
__Mgfun[`sys*sys`]__
:

`> `
**sys:=`sys*sys`(sys1,sys2);**