Symbolic arrays with underscore names have broken latex representation

[cstjean]

On Symbolics 6.13, a variable array with an underscore, like @variables A_out[1:10] has broken HTML when accessing its elements, A_out[1]

Presumably the whole subscript ought to be enclosed in {}

[karlwessel]

A similiar problem happens when displaying an element of a part of a symbolic array:

using Symbolics

julia> @variables z[1:3]
1-element Vector{Symbolics.Arr{Num, 1}}:
 z[1:3]

julia> using Latexify

julia> latexify(z[1:2][1])
L"\begin{equation}
z_{\left[
\begin{array}{c}
1 \\
2 \\
\end{array}
\right]}_{1}
\end{equation}
"

Here is the latex-error for the above output: http://www.texrendr.com/?eqn=%5Cbegin%7Bequation%7D%0Az_%7B%5Cleft%5B%0A%5Cbegin%7Barray%7D%7Bc%7D%0A1%20%5C%5C%0A2%20%5C%5C%0A%5Cend%7Barray%7D%0A%5Cright%5D%7D_%7B1%7D%0A%5Cend%7Bequation%7D

When there are two subscripts one needs to clarify by curly braces which is the subscript of which.

[ChrisRackauckas]

Thanks for the reports. I don't know if I'll get to this soon, but just dropping it that our recipes just tell Latexify to use subscript https://github.com/JuliaSymbolics/Symbolics.jl/blob/master/src/latexify_recipes.jl#L88 so my guess is that this can be MWE'd to be a Latexify recipe issue with repeated subscripts. I haven't gotten as far as building an example though, but that would be the next step to get an error onto Latexify which should be the root cause.

[karlwessel]

Thanks for the hint! I constructed a MWE and created an issue with Latexify.jl.

[karlwessel]

PR #1303 didn't fix my use case, but with korsbo/Latexify.jl#316 it now compiles and looks ok:

julia> latexify(z[1:2][1])
L"\begin{equation}
\left( z_{\left[
\begin{array}{c}
1 \\
2 \\
\end{array}
\right]} \right)_{1}
\end{equation}
"

Renders as

$$\left( z_{\left[ \begin{array}{c} 1 \\ 2 \\ \end{array} \right]} \right)_{1}.$$

[ChrisRackauckas]

Okay, that's a reasonable representation.