daigo75

// Step 1 - Keep track of cart contents
add_action('wp_loaded', function() {
  // This variable must be global, we will need it later. If this code were
  // packaged as a plugin, a property could be used instead
  global $allowed_cart_items;
  // We decided that products with ID 737 and 832 can go together. If any of them
  // is in the cart, all other products cannot be added to it
  $restricted_cart_items = array(
    737,
    832,