riance matrix). The type
<code>cholesky_factor_corr</code> is for Cholesky factors of correlation
matrices (lower triangular, positive diagonal, unit-length rows).</p>
<p>Constraints provide error checking for variables defined in the
<code>data</code>, <code>transformed data</code>, <code>transformed parameters</code>,
and <code>generated quantities</code> blocks. Constraints are critical for
variables declared in the <code>parameters</code> block, where they
determine the transformation from constrained v