Issue title: State change in scripts
 Issue body: R_\mathfrak{e} should work.
 Comments: 
 Comment 0: Update, this is true for macro arguments as well.  For instance, the following fails to parse:
`\frac\mathfrac{e}2` which should parse like `\frac{\mathfrac{e}}{2}`
{'source': 'GithubIssues', 'repo_name_with_owner': 'ReTeX/ReX', 'issue_id': 202693755, 'repo_stars': 106.0}