diff and pdiff method of class Mv throws exception when differentiate by a coordinate symbol about galgebra

[mammalwong]

pdiff method of Mv class also throws the same exception when invoking (x*ex).pdiff(x).

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AttributeError Traceback (most recent call last)
in <cell line: 1>()
----> 1 (x*ex).pdiff(x)

1 frames
/usr/local/lib/python3.10/dist-packages/galgebra/ga.py in pDiff(self, A, coord)
2050 # variable, but including case of non-constant basis vectors
2051
-> 2052 dA = self.mv(expand(diff(A.obj, coord)))
2053
2054 if self.connect_flg and self.dslot == -1 and not A.is_scalar(): # Basis blades are function of coordinates

AttributeError: 'Mul' object has no attribute 'obj'