parsing - Detecting cycles in Syntax Directed Definitions.. Exponential? -

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I'm studying syntax guided definition from "Compiler: Principles, Techniques and Tools Aho, Ulman, Sethi and Lam" I had come in the following line in reference to the circular dependence of the characteristics in the parse tree:

It is computationally difficult to determine whether any tree in any tree SDD Un in the tree It may also be argued (section: 5.1.2)

It also mentions that

is the complexity of exponential time in detecting chakras

But there are elements of Tarejen's firmly connected algorithms that can get cycles in O (E + V). So are the above sources opposing this?

Can anyone tell me what am I missing?

To find a circle in some purse tree, call it o (e + v) but this problem is not the problem

is determined that it exists in any of the circulars present in any of the parse trees That may have to be translated to the given SDD. (Emphasis has been given).

This is a more difficult problem.


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