Until yesterday the recommended way to use the Dummy class was with Symbol('x',
dummy=True). While I agree that the new syntax is better, we should take a
more cautious approach in removing the old syntax. According to git blame, it
has been described in the user guide since 2008 and Dummy
The current instantiation of dummies using the workaround fix for anticipated
polys12 behavior doesn't work properly:
h[1] x=symbols('x', cls=Dummy)
h[1] type(x)
type 'list'
h[2] x
[_x]
This commit fixes this and tests are added. Should we also allow other classes
beside
