%flow fg4: \flowchart{\flowstart\flowmark0 \flowcompute{$F=1$}\flowmark1 \flowinput{$\quad n\quad$} \flowdecide{}{no}{yes}{$n$ integer} \flowdecide{$<$}{$=$}{$>$}{$n$ : 0} \flowcompute{$i=0$}\flowmark2 \flowcompute{$i=i+1;$ $F=F\times i$} \flowdecide{yes}{}{no}{$i