Consider the $($true$)$ statement: $``$It is undecidable whether or not a

given context$-$free grammar is ambiguous.$\text{'}\text{'}$

$\backslash$begin$\{$enumerate$\}$

$\backslash$item Undecidability is a property of languages. Use set notation

to define the

language $L$\_\{$amb$\}$$ being referred to in the statement. $($It may be helpful

to look at something such as the definition of the Accept

language.$)$