Need help with o-thread-blockcall

Thanks for some mind-blowing elisp work!

Just trying to figure out how to use `o-thread-blockcall`

Basically I want to use `#begin_rename` with a fixed list
And then wrap it in `#begin_eqnarray*`

Currently I hacked this far
Which basically cutpasted your `rename` block and hardcoded (one element of) the list I want replaced.
`goftex` is the block I want -- gofer as Latex equations
```
(o-defblock goftex (list "-> to \\leftarrow") nil
(s-replace-all
(--map (cons (car it) (cadr it))
(--map (s-split " to " (s-trim it))
(s-split "," list)))
contents))

```

Obviously I'd prefer to _reuse_ your `rename` not cutpaste it!
The other thing is that in the current attempt, org is not recognizing `#begin_eqnarray` if it is mixed with my `goftex`.
Result of that is that I get extra `\(` and `\)` enclosing the `\leftarrow` inside the `begin{eqnarray*}`