-- -*- M2-comint -*- hash: -1637860046

i1 : B = skewPolynomialRing(QQ,(-1)_QQ,{x,y,z,w})
--Calling Bergman for NCGB calculation.
Complete!

o1 = B

o1 : NCQuotientRing

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

o2 = NCRingMap B <--- B

o2 : NCRingMap

i3 : C = oreExtension(B,sigma,a)
--Calling Bergman for NCGB calculation.
Complete!

o3 = C

o3 : NCQuotientRing

i4 : sigmaC = ncMap(C,C,{y,z,w,x,a})

o4 = NCRingMap C <--- C

o4 : NCRingMap

i5 : normalElements(sigmaC,1)

o5 = | a |

o5 : NCMatrix

i6 : normalElements(sigmaC,2)

o6 = 0

              1
o6 : Matrix QQ  <--- 0

i7 : normalElements(sigmaC @@ sigmaC,2)

o7 = | a^2 |

o7 : NCMatrix

i8 : 
