[NTG-context] \to in footer?

Hi to all, I wanted to use in footer an arrow so I went with: \setupfootertexts[$\to$ help] It raises an error. I solved with $\rightarrow$, but I was curious about this fact Why does it happen? many thanls -a- Andrea Valle DAMS - Facoltà di Scienze della Formazione Università degli Studi di Torino http://www.semiotiche.it/andrea andrea.valle@unito.it