-- -*- M2-comint -*- hash: 5377162271956629996

i1 : B = skewPolynomialRing(QQ,(-1)_QQ,{x,y,z,w})

o1 = B

o1 : FreeAlgebraQuotient

i2 : sigma = map(B,B,{y,z,w,x})

o2 = map (B, B, {y, z, w, x})

o2 : RingMap B <-- B

i3 : C = oreExtension(B,sigma,a)
Warning:  F4 Algorithm not available over current coefficient ring or inhomogeneous ideal.
Converting to Naive algorithm.

o3 = C

o3 : FreeAlgebraQuotient

i4 : B = toFreeAlgebraQuotient(QQ[x])

o4 = B

o4 : FreeAlgebra

i5 : sigma = map(B,B,{x})

o5 = map (B, B, {x})

o5 : RingMap B <-- B

i6 : delta = derivation(B,{1_B})

o6 = Derivation{generators => HashTable{x => 1}   }
                homomorphism => map (B, B, {x})
                "imageCache" => MutableHashTable{}
                matrix => | 1 |
                source => B

o6 : Derivation

i7 : C = oreExtension(B,sigma,delta,dx)
Warning:  F4 Algorithm not available over current coefficient ring or inhomogeneous ideal.
Converting to Naive algorithm.

o7 = C

o7 : FreeAlgebraQuotient

i8 : 
