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

I try the following codes, but it does not work. SF= SymmetricFunctions(QQ) s=SF.s() 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'

 2 None FrédéricC 4473 ●3 ●37 ●94

### 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'