This morning I created a Drupal Rules module rule set component, which is being triggered with a reaction rule. Some of the rules in the set have actions that will trigger the reaction rule, but recursion isn't happening. This is good, I don't want any recursion.
To be on the safe side I searched to find out why recursion isn't happening.
We can see that in rules_element_invoke_component() recursion is being intentionally prevented.