Get variables of parent (caller) function with reflection?

i.e. I have no access to parent:

function parent()
{
  $xyz="hello";
  child();
}

function child()
{
   //any way to get the value of   $xyz
}

Is Reflection able to do that?

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btw, in advance: please don't comment like "why you need that" or etc, I am long ago tired explaining why i need this or that.