Check if a user/guest has purchased specific products in WooCommerce
<p>I need to check if a customer has purchased a specific product earlier in WooCommerce. </p>

<p>The case is this: The customer shall not be able to purchase product "c", "d", "e" unless they have purchased product "a" or "b" at an earlier time.</p>

<p>If the customer has purchased product "a" or "b" earlier, then the purchase button of product "c", "d" and "e" is activated and they are allowed to buy them. </p>

<p>If they haven´t purchased "a" or "b" earlier, they will not be allowed to purchase "c", "d", "e" and the purchase button is deactivated.</p>

<p>How can I achieve this? </p>

<p>Thanks.</p>