Neurosymbolic Learning of Interpretable World Models
Organizations: Fondazione Bruno Kessler · Free University of Bozen-Bolzano · Vrije Universiteit Amsterdam
Abstract
World models aim to learn compact representations of an environment from observations, enabling agents to predict future states and plan their behaviour. However, most existing approaches learn black-box representations, with limited ability to incorporate prior knowledge about the world. We introduce Concept-Grounded World Models (CGWMs), a neurosymbolic world model design that instead learns interpretable concept representations. We learn these concepts from observations using explicit and complete knowledge, expressed in temporal logic, that specifies the valid world states and the temporal relations governing their dynamics. Furthermore, we directly use this knowledge by formulating planning as differentiable reasoning, optimising the agent's actions by gradient ascent to satisfy a goal. We experimentally compare CGWM with a purely neural baseline and a neurosymbolic baseline on two game environments. We find that CGWMs ground concepts much more accurately, even over long horizons, resulting in significantly more robust planning both in and out of distribution.
Figures & tables
| Two Rooms | Ice Slider | ||||||
|---|---|---|---|---|---|---|---|
| easy | medium | hard | lava dense | periodic door | |||
| CGWM (Gödel Trick) | 100.0 (0.0) | 100.0 (0.0) | 96.3 (0.8) | 88.4 (2.8) | 94.9 (1.0) | 100.0 (0.0) | 100.0 (0.0) |
| CGWM (log-product) | 100.0 (0.0) | 100.0 (0.0) | 90.4 (1.9) | 68.6 (5.5) | 84.3 (3.3) | 99.8 (0.4) | 90.4 (1.7) |
| LeWM | 95.8 (1.2) | 37.8 (2.8) | 22.0 (9.0) | 9.6 (6.9) | 7.2 (3.6) | 69.1 (12.6) | 3.6 (2.9) |
Appendix figures & tables7 assets
Supplementary material from the paper’s appendix.
Appendix
| Operator | Abbreviation | Description |
|---|---|---|
| Weak next ( ) | If there is a next instant, holds at it. | |
| Eventually ( ) | holds at some instant of the trace. | |
| Globally ( ) | holds at every instant of the trace. | |
| Release ( ) | holds up to and including the first instant at which holds; if never holds, holds throughout the trace. | |
| Strong release ( ) | As release, but is required to hold at some instant. | |
| Weak until ( ) | As until, but is not required to hold; if it never does, holds throughout the trace. |
| Formula | Meaning |
|---|---|
| Specification formulas | |
| The agent eventually reaches the goal. | |
| Constraints | |
| The agent is on the goal only at the last time step. | |
| There is exactly one agent. | |
| There is exactly one goal. | |
| Formula | Meaning |
|---|---|
| Specification formulas | |
| The agent eventually reaches the goal. | |
| The agent eventually steps on lava. | |
| The door is eventually open. | |
| Constraints | |
| The agent is on the goal only at the last time step. | |
| Formula | Meaning |
|---|---|
| The door stays closed until the button is pressed, and alternates between open and closed afterwards, unless the agent is on it. | |
| The agent moves as in Two Rooms (hard), with the door of the next time step blocking it, and it stays in forever once the door closes on it. | |
| , for | Walls, lava, button and goal do not move. |
| Static concepts | Dynamic concepts | All concepts | |||||||
| CGWM (log-product) | |||||||||
| 3200 | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) |
| 800 | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) |
| 200 | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) |
| 50 | 0.97 (0.07) | 0.97 (0.07) | 1.00 (0.00) | 0.98 (0.05) | 0.97 (0.08) | 0.98 (0.07) | 0.98 (0.06) | 0.98 (0.05) | 0.98 (0.07) |
| Static concepts | Dynamic concepts | All concepts | |||||||
| CGWM (log-product) | |||||||||
| 3200 | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) |
| 800 | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) |
| 200 | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) |
| 50 | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) | 1.00 (0.00) |
| Two Rooms | Ice Slider | ||||||
| easy | medium | hard | lava dense | periodic door | |||
| Gödel | |||||||
| Gödel Trick | 100.0 (0.0) | 100.0 (0.0) | 96.3 (0.8) | 88.4 (2.8) | 94.9 (1.0) | 100.0 (0.0) | 100.0 (0.0) |
| softmax | 100.0 (0.0) | 84.4 (3.4) | 88.5 (2.6) | 86.2 (3.5) | 81.7 (4.1) | 100.0 (0.0) | 100.0 (0.0) |
| log-product | |||||||
| Gumbel-Softmax | 100.0 (0.0) | 100.0 (0.0) | 90.4 (1.9) | 68.6 (5.5) | 84.3 (3.3) | 99.8 (0.4) | 90.4 (1.7) |