Better error message for non-co-safe properties in R operators.

git-svn-id: https://www.prismmodelchecker.org/svn/prism/prism/trunk@10351 bbc10eb1-c90d-0410-af57-cb519fbb1720

prism/src/explicit/ProbModelChecker.java

@@ -1026,7 +1026,7 @@ public class ProbModelChecker extends NonProbModelChecker
 		else if (Expression.isCoSafeLTLSyntactic(expr)) {
 			return checkRewardCoSafeLTL(model, modelRewards, expr, minMax, statesOfInterest);
 		}
-		throw new PrismException("Invalid contents for an R operator: " + expr);
+		throw new PrismException("R operator contains a path formula that is not syntactically co-safe: " + expr);
 	}
 	
 	/**

prism/src/prism/NondetModelChecker.java

@@ -1189,7 +1189,7 @@ public class NondetModelChecker extends NonProbModelChecker
 		else if (Expression.isCoSafeLTLSyntactic(expr)) {
 			return checkRewardCoSafeLTL(expr, stateRewards, transRewards, min);
 		}
-		throw new PrismException("Invalid contents for an R operator: " + expr);
+		throw new PrismException("R operator contains a path formula that is not syntactically co-safe: " + expr);
 	}
 	
 	// reach reward

prism/src/prism/ProbModelChecker.java

@@ -863,7 +863,7 @@ public class ProbModelChecker extends NonProbModelChecker
 		else if (Expression.isCoSafeLTLSyntactic(expr)) {
 			throw new PrismNotSupportedException("Co-safe reward properties not yet supported for DTMCs in this engine");
 		}
-		throw new PrismException("Invalid contents for an R operator: " + expr);
+		throw new PrismException("R operator contains a path formula that is not syntactically co-safe: " + expr);
 	}
 	
 	// reach reward