# Kronecker 0 0 form

+1 vote

Now with all the substitution rules I have ended up with a term like

$${}Ricci = -6\partial_{0}{}^{0}{a} {a}^{-3}-16\partial_{0}{a} \partial^{0}{a} {a}^{-4}+16\delta_{0}{}^{0} \partial_{0}{a} \partial^{0}{a} {a}^{-4}$$

Notice the $\delta_{0}{}^{0}$.

I can't figure out how to substitute this away, it gets turned into one right away in the substitution rule and therefore the pattern can't match.

related to an answer for: Only one component of derivative non zero

Forgot to mention that doing an eliminate_kronecker doesn't help

You wrote as a separate question (please don't do that):

"Meant to say that simplifying to one immediately is the problem, since the /delta 0 0 term was created in a prior substitution rule somehow through some combination of things. Now I cannot get rid of it because of the immediate conversion.

Does that make sense?"

No, I don't understand. Does it, or does it not keep the \delta^{0}_{0} in your expression? If it does, that's a bug, please send me a sample notebook that shows it (try to trim it down to minimal form).

Never mind, I see how this can happen. Will fix.

\delta{#}::KroneckerDelta;
ex:= \delta^{0}_{0};