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+# Justification
+1. Introduce the situation
+	1. lab owner building that leaks heat.
+	2. Need to control the temperture, provide requirment
+	3. But lab is actually variable. conditions change (perturbation)
+	4. A robust controller C meets the requirement for all plants in the set P
+2. This is doable with the model of the controller
+	1. But is this the same with an actual controller?
+	2. No. There is some layers of abstraction removed in making a real unit
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