 algebra
            algebra    単射(one-to-one),全射(surjection),全単射(bijection)/双射
        単射の定義\begin{align} x_1 \ne x_2 \implies f(x_1) \ne f(x_2) \end{align}または \begin{align} f(x_1) = f(x_2) \implies x_1 = x_...      
                        
     algebra
            algebra     algebra
            algebra     algebra
            algebra     algebra
            algebra     algebra
            algebra