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Results tagged with ambiguity
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user 9612
Questions about ambiguity in context-free grammars.
9
votes
When is the concatenation of two regular languages unambiguous?
Updated (thanks to Yuval Filmus).
Given two languages $X$ and $Y$ of $A^*$, let
\begin{align}
X^{-1}Y &= \{u \in A^* \mid \text{there exists $x \in X$ such that $xu \in Y$} \} \\
YX^{-1} &= \{u \in …
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