We have a scientist who, as I have since seen proved, had no rival.中的as I have since seen proved没有看懂,怎么多了个since 请大虾们指点
答：主句：We have a scientist who had no rival. 我们有一个科学家,他曾经是举世无双的.（没有对手的）
as 从句=是一个非限制性定语从句,类似于as is known to all.之类的.as指上面讲的后半句话：他曾经是举世无双的. 这一点,正如,I have seen it proved since. since是副词,作状语表示“打那以来”,和现在完时连用.这一点,正如我已经看到的是已经证明了的.