b=[arrow2d(tailpoint=(0, 0), headpoint=(1,4), color='red', legend_label="$V_{R_{1}}$", legend_color='black'),
   arrow2d(tailpoint=(0, 0), headpoint=(1,3), color='yellow', legend_label="$V_{Y_{1}}$", legend_color='black'),
   arrow2d(tailpoint=(0, 0), headpoint=(1,2), color='blue', legend_label="$V_{B_{1}}$", legend_color='black'),
   arrow2d(tailpoint=(0, 0), headpoint=(1,1), color='green', legend_label="$3V_0$", legend_color='black',width=2)]
sum(b)