### can incidence algebras over ring that is not number ring?

I try the following codes, but it does not ~~work.
~~work.

```
SF= SymmetricFunctions(QQ)
```~~s=SF.s() ~~s = SF.s() ~~I=P.incidence_algebra(SF)
~~I = P.incidence_algebra(SF)
s([2,1])*I[1,1]

TypeError: unsupported operand parent(s) for *: 'Symmetric Functions over Rational Field in the Schur basis' and 'Incidence algebra of Finite lattice containing 4 elements over Symmetric Functions over Rational ~~Field'~~Field'