t-hand side of the assignment
must be assignable to the type of the variable being declared. For
example, it is legal to have</p>
<pre class="stan"><code>real sum = 0;</code></pre>
<p>even though <code>0</code> is of type <code>int</code> and <code>sum</code> is of type <code>real</code>, because
integer-typed scalar expressions can be assigned to real-valued scalar
variables. In all other cases, the type of the expression on the
right-hand side of the assignment must be identical to the type of the
variabl