Figure 4: Parallel hierarchies of language and cognition consist of lower-level concepts (like situations consist of objects). A set of objects (or lower-level concepts) relevant to a situation (or higher-level concept) should be learned among practically infinite number of possible random subsets (as discussed, larger than the Universe). No amount of experience would be sufficient for learning useful subsets from random ones. The previous section overcame combinatorial complexity of learning, given that the sufficient information is present. However, theories of mathematical linguistics offer no explanation where this information would come from.