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+1 vote

There seems to be a bug in expand_delta, or I am making a syntax error of some sort. (I am running the most recent build.)

My code is as follows:

ex := \delta^{a}_{b}^{c}_{d};

The error is:

RuntimeError: tree: attempt to navigate up past head node. At:   <string>(6): <module>
in Bug reports by (540 points)

1 Answer

+1 vote

This only seems to happen when the delta appears at the very top of the expression (so not in a product or sum). Now fixed on github, thanks for reporting.

by (71.6k points)

Thanks, Kasper! I should have realized that was what it was complaining about...