动画中的显示属性动画是什么？

Question

According to the svg Animate Element document animate is additive; but when I am trying to use 2 animate tag with attribute name=display , I am getting only the effect of later one in firefox 23.0 and opera 12.15, here is My svg file ;

and Here is two animate tag

 <animate attributeName="display" begin="0" dur="10" calcMode="discrete"  fill="remove" additive="sum" keyTimes="0;0.5;1" values="inherit;none;inherit" />
 <animate attributeName="display" begin="0" dur="10" calcMode="discrete" fill="remove" additive="sum" keyTimes="0;0.2;.8;1" values="inherit;none;inherit;none" />

I like to know if display is the special attribute for animate? or it is a bug in those two browsers?

Answer 1

显示属性是SVG规范表中 “可动画属性和属性中使用的所有其他数据类型”之一，该属性定义了某些内容是否可动画并且读取答案是否为“否”，这不是可加的。