scoring strategy formula NB, NM and NMC (Support #640)

The second strategy works, the first does not work (it always gives 0).
Anyu idea how to obtain the first strategy?
Thanks
Giovanni

I would like this to give
1 point if 0 or 1 wrong answers are given (unchecked correctchoice or checked wrongchoice)
0 point if more than 1 wrong answer is given

\begin{questionmult}{C1ALG02Q021a}\scoring{formula=(NM>=2 ? 0 : 1)}

\begin{choicescustom}
\correctchoice{$e$}
\correctchoice{$g$}
\correctchoice{$h$}
\wrongchoice{$a$}
\wrongchoice{$b$}
\wrongchoice{$c$}
\wrongchoice{$d$}
\wrongchoice{$f$}
\end{choicescustom}
\end{questionmult}

I would like this to give
0 if more than 1 wrongchoice is checked and
0,33 or 0,66 or 0,99 depending if 1, 2 or 3 correctchoices are checked and no wrongchoices are checked

\begin{questionmult}{C1INF01Q006a}\scoring{default.v1=0,default.v2=0,default.v3=0,formula=(NMC>=1 ? 0 : v1+v2+v3)}
%\begin{minipage}{.3\linewidth}
In una NXOR l'uscita \`e\ $0$ se

\end{minipage}
\begin{minipage}{.6\linewidth}
\begin{multicols}{3}
\begin{choices}
\correctchoice{tutti gli ingressi sono 1.}\scoring{set.v1=.33}
\scoring{b=0.5}
\correctchoice{Un ingresso è 1 e l’altro è 0.}\scoring{set.v2=.33}
%\scoring{b=0.5}
\correctchoice{\`e\ un gruppo universale.}\scoring{set.v3=.33}
%\scoring{b=0.5}
\wrongchoice{tutti gli ingressi sono 0.}
%\scoring{b=0,m=-0.5}
\wrongchoice{gli ingressi sono negati.}
%\scoring{b=0,m=-0.5}
\end{choices}
\end{multicols}
\end{minipage}
\end{questionmult}