Q6 — Rete Net: Vehicle Classification
Luxury-Car, Minivan and Truck all match — Truck's three conditions win specificity, Luxury-Car's ts-107 wins recency.
The Question
A Rete net classifies vehicles. Working memory:
101. (Cargo ^vin A1 ^bed flat)
102. (Passenger ^vin A1 ^limit 2)
103. (Passenger ^vin B2 ^limit 8)
104. (Passenger ^vin C3 ^limit 2)
105. (Power ^vin A1 ^hp 400)
106. (Power ^vin B2 ^hp 250)
107. (Power ^vin C3 ^hp 900)
108. (Wheel ^vin B2 ^tyre regular)
109. (Wheel ^vin C3 ^tyre regular)
| # | Question | Official answer |
|---|---|---|
| 6.1 | Conflict set (A: Luxury-Car,104,107 · B: Minivan,103,106 · C: Truck,101,102,105 · D: Minivan,103,106,108) | A, B, C |
| 6.2 | Specificity fires | C |
| 6.3 | Recency fires | A |
The Topic in 60 Seconds
Alpha nodes filter single WMEs; beta nodes join on the shared ^vin. Conflict set = all full tuples. Specificity = most conditions; Recency = newest max-timestamp.
Deep-dive: The Rete Algorithm.
The joins
Net rules: Luxury-Car = Passenger limit-2 ⋈ Power hp ≥ 700 · Minivan = Passenger limit-8 ⋈ Power hp ≤ 300 · Truck = Cargo bed ⋈ Passenger limit-2 ⋈ Power hp ≤ 500 (all same vin).
| Rule | Join check | Tuple |
|---|---|---|
| Luxury-Car | limit-2 {102: A1, 104: C3} ⋈ hp≥700 {107: C3} → vin C3 | (Luxury-Car, 104, 107) ✓ |
| Minivan | limit-8 {103: B2} ⋈ hp≤300 {106: B2} → vin B2 | (Minivan, 103, 106) ✓ |
| Truck | bed {101: A1} ⋈ limit-2 {102: A1} ⋈ hp≤500 {105: A1} → vin A1 | (Truck, 101, 102, 105) ✓ |
Conflict set = options A, B, C ✓ (D is invalid — Minivan has no Wheel condition.)
6.2 — Specificity → C
Condition counts: Luxury = 2, Minivan = 2, Truck = 3 → most conditions → option C ✓
6.3 — Recency → A
Max timestamps: Luxury → 107; Minivan → 106; Truck → 105. Newest wins → option A ✓
Tricks & Tips
Answers: 6.1 A, B, C · 6.2 C · 6.3 A