# Grammar

| Fact | Macro |
|---|---|
| one legal rewrite | `\sdstep[role=rewrite]{name}{lhs}{rhs}` |
| why it is legal | `\sdreason{name}{text}` |
| a cancelled term | `\sdcancel{name}{math}` |
| substitution | `\sdsubst{name}{from}{to}` |
| focus box | `\sdbox[role=keep]{name}{math}` |
| illegal vs legal | `\sdcol{name}{bad}{good}` (one per figure) |
| bottom | `\sdmeaningbox` (idea / rewrite / caveat) |

Built-in roles: `keep` `rewrite` `cancel` `intro` `warn` `neutral`.