Function unlink 

pub(crate) fn unlink(
    qt: &CxxQtThread<Sioul>,
    shared: &Arc<Shared>,
    a: &str,
    b: &str,
) -> String

Undoes a tie wherever it is written: a task, an event, a note’s front matter, the local file. A step, a wait, a guest or a link in a note’s text are changed where they are: that is said.