arXiv:2603.25975v1 Announce Type: new
Abstract: We show that they do. Schank’s conceptual dependency theory proposed that all events decompose into primitive operations — ATRANS, PTRANS, MTRANS, and others — hand-coded from linguistic intuition. Can the same primitives be discovered automatically through compression pressure alone?
We adapt DreamCoder’s wake-sleep library learning to event state transformations. Given events as before/after world state pairs, our system finds operator compositions explaining each event (wake), then extracts recurring patterns as new operators optimized under Minimum Description Length (sleep). Starting from four generic primitives, it discovers operators mapping directly to Schank’s: MOVE_PROP_has = ATRANS, CHANGE_location = PTRANS, SET_knows = MTRANS, SET_consumed = INGEST, plus compound operators (“mail” = ATRANS + PTRANS) and novel emotional state operators absent from Schank’s taxonomy.
We validate on synthetic events and real-world commonsense data from the ATOMIC knowledge graph. On synthetic data, discovered operators achieve Bayesian MDL within 4% of Schank’s hand-coded primitives while explaining 100% of events vs. Schank’s 81%. On ATOMIC, results are more dramatic: Schank’s primitives explain only 10% of naturalistic events, while the discovered library explains 100%. Dominant operators are not physical-action primitives but mental and emotional state changes — CHANGE_wants (20%), CHANGE_feels (18%), CHANGE_is (18%) — none in Schank’s original taxonomy.
These results provide the first empirical evidence that event primitives can be derived from compression pressure, that Schank’s core primitives are information-theoretically justified, and that the complete inventory is substantially richer than proposed — with mental/emotional operators dominating in naturalistic data.