Feature proposal : update proof when exchanging hypotheses

[emiquey]

A nice feature that could be added would be to be able to exchange formulas below a ⊗-intro rule and to have the premises updated. For instane, consider the following bad attempt . When you realize that you should have first exchanged then use the ⊗-intro rule, you have to remove the rule/exchange/⊗-intro again. I don't if it makes sens in any other situation (that is, lower in a tree), and if it would be hard to add, but if it is not too much work I think it's worth it !

[emiquey]

When you realize that you should have first exchanged then use the ⊗-intro rule, you have to remove the rule/exchange/⊗-intro again.

Short answer to this (when there is only one ⊗-intro rule above): actually it is not the case, since you can just exchange the formulas then click on the appropriate tensor and it does the job.

[olaure01]

For situations with a tentative modification deeper in the proof, you may face additional difficulties:

• multiple modifications may be necessary
• since exchanges are recorded as a single permutation at the level of each sequent, it may be difficult to route the moved formula up in the tree