How to quote from the same document? For example
SECTION 3. Explanation
Before discussing the main theorem, let's quote it's statement.
Theorem 7.1. (Main lemma) 1 + 1 = 2
...
SECTION 7. Appendix
Theorem 7.1. (Main lemma) 1 + 1 = 2
Notice that I'd like the theorem be numbered as "7.1." even in section 3. This cannot be done simply by copying and pasting, or by using packages like clipboard.
Putting it differently, I'd like to copy a specific region shown in the compiled file and paste to another.
thmtoolspackage enables you to define restatable theorems. See §1.4, Repeating theorems, pp. 6-7 in the documentation. – Bernard Nov 15 '20 at 12:33\begin{docoment}, but let the appendix be displayed as the last section? I hope then the undefined control sequence issue will be resolved. – Student Nov 15 '20 at 19:48\begin{restatable}[Euclid]{theorem}{firsteuclid}...\end..., I put\firsteuclid*one line before the restatable declaration. Then the undefined control sequence is! Undefined control sequence. \n l.1586 \firsteuclid. Putting\firsteuclid*one line after the end of declaration worked fine. – Student Nov 15 '20 at 20:31