LangGraph Structural Specification

This graph utilizes a centralized Hub-and-Spoke (Supervisor) routing topology.

Nodes

1. router: The central supervisor.
2. planner: The LLM logic hub.
3. adder: Worker node.
4. subtractor: Worker node.
5. multiplier: Worker node.
6. divider: Worker node.

Routing Edges

From Router:

• If error_context exists -> END
• If current_expression is a standalone number -> Set final_value, route to END
• Else -> planner

From Planner:

• Reads next_target_op["op"].
• Routes to adder, subtractor, multiplier, or divider based on the value.
• If missing or malformed -> END.

From Math Agents:

• Execute calculation.
• If error_context is raised (e.g. DIV_ZERO) -> END
• Else -> Route back to router for the next cycle.