Without it, there is no way to ensure that a Jam mixin type will be valid across all possible instantiations.

没有它，就无法确保Jam mixin类型将在所有可能的实例化上都是有效的。

youdao

Ambiguous overloading is a problem because method arguments may be of mixin type, allowing for situations in which two overloaded methods are applicable and neither is more specific.

不明确的重载是个问题，因为方法参数可能是mixin类型，它允许两个已重载的方法可用并且这两个方法都不是比较特定的情况。

youdao

Also notice that the type checker can't even check that every instantiation of a mixin will result in valid super-constructor calls.

而且请注意，类型检查器甚至不能检查是否每个mixin实例化都会产生有效的超级构造函数调用。

youdao