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+1 vote


When I run the following code through Cadabra


eqtn := A^{f} A^{m} B_{g f} G^{a}_{m e} G^{e}_{b d}.

substitute (eqtn,$A^{e} B_{c e} G^{a}_{b d} -> A^{f} B_{f} R^{a}_{b c d}$);

it reports an exception: Triple index m inside a single factor found.

A triple m-index seems odd as there are only two m-indices in the expression (maybe an extra m-index pops up during the substitute).

This same code runs without error in Cadabra 1.16 and 1.41.

Cheers, Leo

in Bug reports by (1.6k points)

1 Answer

+1 vote
Best answer

Caused by an optimisation in 2.x which had some unintentional side effects. Now fixed on github. Also fixes the other problem you reported (https://cadabra.science/qa/598/curious-behaviour-in-substitute).

by (70.8k points)
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Thanks Kasper, it works, Cheers, Leo