Tom presented the current status of the instruction set with the intent of partially preparing the developers for the task of writing network ancestors. The instruction sets, is the one part of Tierra for which Tom has reserved the task of coding exclusively to himself. This is a bit odd as he is probably the least qualified for the job.
The instruction set code has been developed over a period of years. Therefore preparation for this presentation required that he review the code to refresh his memory. This review process revealed a number of bugs, inconsistencies and confusions, which were (hopefully) corrected. However, there are many new instruction that have never been put to use, and so no doubt more bugs remain which will only be revealed when the new instructions are used.