owing definitions are legal.</p>
<pre class="stan"><code>e = d[1];        // result is array of matrices
f = d[1,3];      // result is matrix
f = e[3];        //   same result as above
g = d[1,3,2];    // result is row vector
g = e[3,2];      //   same result as above
g = f[2];        //   same result as above
x = d[1,3,5,2];  // result is scalar
x = e[3,5,2];    //   same result as above
x = f[5,2];      //   same result as above
x = g[2];        //   same result as above</code></pre>
<p>As shown, the resu