imported patch rewardcounter-DTMC-no-negative.patch

prism/src/explicit/CounterTransformation.java

@@ -174,6 +174,9 @@ public class CounterTransformation<M extends Model> implements ModelExpressionTr
 			Integer rewStruct = bounds.get(0).getResolvedRewardStructIndex();
 
 			rewards = (MCRewards) mc.constructRewards(originalModel, rewStruct);
+			if (rewards.hasNegativeRewards()) {
+				throw new PrismException("Can not perform counter transformation in the presence of negative rewards");
+			}
 			break;
 		}
 		case DEFAULT_BOUND: