• If the soil moisture is low (L) and the weather conditions are dry (D), the system should decide to water the plants (Y).
• If the soil moisture is low (L) regardless of the weather conditions (W), the system should decide to water the plants (Y).
• If the soil moisture is high (H) and the weather conditions are dry (D), the system should decide to water the plants (Y).
• If the soil moisture is high (H) and the weather conditions are wet (W), the system should decide not to water the plants (N), as the soil already has sufficient moisture.

This truth table captures a simple logic for the smart irrigation system based on soil moisture and weather conditions.