partial parallel vecsearch

parvecsearch(v,x)={
                             b=0;
                             parfor(y=1,#v,
                                       b=b+1;
                                       (v[y]==x),
                                       z,
                                      if(z,
                                         return(1),
                                         if(b==#v,
                                            return(0)
                                           )
                                        )
                                     )