That&#x27;s a simplistic view. A grammar might not be a 1:1 mapping to an AST (where the AST is just a reduction of a higher-level construct set). Also, an AST is really a generic term, and can mean anything from a parsed representation of the grammar to the final stage of the output code.<p>The classical example I give when I ask this question, is how do I represent the concept of an abstract &quot;record&quot; (or structure) in any visual language. How do I convey the mapping from definition to instance of any given construct?<p>These are <i>though</i> problems to represent in a visually compelling and <i>useful</i> way.