removing indirect left recursion I want to remove indirect left recursion from these rules:
    S--&gt;TU,
    T--&gt;US|b,
    U--&gt;ST|a

I don't know if I can implement the algorithm correctly. My assumption is to make it like this:
S--&gt;TU, T--&gt;U'b, U'b--&gt;U'a

Is this correct?
No. The first language is non empty (e.g., it contains the word &quot;ba&quot;), while the second language is empty.