1.8 Virtually and Robotically Embodied AI 11 tokens (Atoms) in the AtomSpace, allowing it to be located by various cognitive processes, and associated with other memory items of any type. So for instance an OpenCog AI system has an AtomSpace, plus some specialized knowledge stores linked into the AtomSpace; and it also has specific algorithms acting on the AtomSpace and appropriate specialized stores corresponding to each type of memory. Each of these algo- rithms is complex and has its own story; for instance (an incomplete list, for more detail see the following section of this Introduction): e Declarative knowledge is handled using Probabilistic Logic Networks, described in Chapter 34 and others; e Procedural knowledge is handled using MOSES, a probabilistic evolutionary learning algo- rithm described in Chapter 21 and others; e Attentional knowledge is handled by ECAN (economic attention allocation), described in Chapter 23 and others; e OpenCog contains a language comprehension system called RelEx that takes English sen- tences and turns them into nodes and links in the AtomSpace. It’s currently being ex- tended to handle Chinese. RelEx handles mostly declarative knowledge but also involves some procedural knowledge for linguistic phenomena like reference resolution and semantic disambiguation. But the crux of the CogPrime cognitive architecture is not any particular cognitive process, but rather the way they all work together using cognitive synergy. 1.8 Virtually and Robotically Embodied AI Another issue that will arise frequently in these pages is embodiment. There’s a lot of debate in the AI community over whether embodiment is necessary for advanced AGI or not. Personally, we doubt it’s necessary but we think it’s extremely convenient, and are thus considerably interested in both virtual world and robotic embodiment. The CogPrime architecture itself is neutral on the issue of embodiment, and it could be used to build a mathematical theorem prover o