title: How to prove that a grammar is ambigous/unambigous?
body: <p>If we have the the grammer 
  <a href="https://i.stack.imgur.com/1dDIf.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/1dDIf.png" alt="Latex Image"></a></p>
  
  <p>how to correctly prove that this is unambigious? In my opinion it's hard to describe it so is there a mathematical or logic proof for that?</p>
  
  <p>And then how to proove that L(G) = G? Next thing where it is hard for me to give a logic proof.</p>
  
  <p>Hope somebody can help.</p>