The standard transposition is the involution of the Weyl algebra which sends x^{a}d^{b} to (-d)^{b}x^{a}. It provides the equivalence in the Weyl algebra between left and right D-modules.
i1 : makeWA(QQ[x,y]) o1 = QQ[x..y, dx, dy] o1 : PolynomialRing, 2 differential variables |
i2 : L = x^2*dy + y*dy^2 + 3*dx^5*dy 5 2 2 o2 = 3dx dy + x dy + y*dy o2 : QQ[x..y, dx, dy] |
i3 : Dtransposition L 5 2 2 o3 = 3dx dy - x dy + y*dy + 2dy o3 : QQ[x..y, dx, dy] |
The standard transposition of a left ideal should be a right ideal, however M2 currently doesn't support right modules. Thus the output is left ideal generated by the transposition of the previous generators.
The object Dtransposition is a method function.