How does one mess with wmes on the IO link?
The rule that is commonly used is: • If a WME is added with add-wme(), then it must be deleted with remove-wme() • If a WME is added via productions/pref memory, then it is always deleted via productions/pref memory. However, this raises another issue. Currently in Soar, you *can* use remove-wme to remove something that was created by productions through preference memory. The problem is that it removes the WME, but does not remove the preference. This can lead to all sorts of nastiness. For example, say a rule created something you want to get rid of, and maybe you want the production to fire again to change the same attribute to have a different value. You use remove-wme to delete the old value. The production can fire again (maybe it fires again because it tests for the absence of the value it’s creating), and it creates a preference for the new value of the attribute. Bingo, you now have an attribute tie impasse. At least that’s what you got in Soar 7. Soar 8 has no attribute tie i
