Drupal form #states using OR I am trying to make a part of my form display depending on the state of a select box. The select box code is:

$form['product_type'] = array(
    '#type' =&gt; 'select',
    '#title' =&gt; t('Product Type'),
    '#options' =&gt; array(
      'a' =&gt; t('a'),
      'b' =&gt; t('b'),
      'c' =&gt; t('c'),
    ),
    '#required' =&gt; TRUE,
  );


I then have a field when I only wan to show it when the value is b or c.

$form['problem'] = array(
    '#type' =&gt; 'textarea',
    '#title' =&gt; t('Problem'),
    '#states' =&gt; array(
      'visible' =&gt; array(
        array(
           ':input[name="product_type"]'=&gt; array('value' =&gt; 'b'),
           ':input[name="product_type"]'=&gt; array('value' =&gt; 'c'),
        ),       
      ),
    ),    
  );


What is happening is that what ever the last value in the page is being used.
I have found the following pages https://api.drupal.org/api/drupal/includes%21common.inc/function/drupal_process_states/7 &amp; https://drupal.org/node/1464758 but am still lost.
it is no right at all, this is the right way to make an OR:

$form['problem'] = array(
  '#type' =&gt; 'textarea',
  '#title' =&gt; t('Problem'),
  '#states' =&gt; array(
    'visible' =&gt; array(
      array(
        ':input[name="product_type"]'=&gt; array(
          array('value' =&gt; 'b'),
          array('value' =&gt; 'c'),
        ),
      ),
    ),
  ),
);


Regards