Removed default values for prctl, csl and ltl settings and added

test formulas for the "die" test as prctl file

src/utility/Settings.cpp

@@ -137,9 +137,9 @@ void Settings::initDescriptions() {
 		("test-prctl", bpo::value<std::string>(), "name of prctl file")
 		("trafile", bpo::value<std::string>()->required(), "name of the .tra file")
 		("labfile", bpo::value<std::string>()->required(), "name of the .lab file")
-		("prctl", bpo::value<std::string>()->default_value(""), "text file containing prctl formulas")
-		("csl", bpo::value<std::string>()->default_value(""), "text file containing csl formulas")
-		("ltl", bpo::value<std::string>()->default_value(""), "text file containing ltl formulas")
+		("prctl", bpo::value<std::string>(), "text file containing prctl formulas")
+		("csl", bpo::value<std::string>(), "text file containing csl formulas")
+		("ltl", bpo::value<std::string>(), "text file containing ltl formulas")
 		("transrew", bpo::value<std::string>()->default_value(""), "name of transition reward file")
 		("staterew", bpo::value<std::string>()->default_value(""), "name of state reward file")
 		("fix-deadlocks", "insert self-loops for states without outgoing transitions")

test/functional/die/testFormulas.prctl

@@ -0,0 +1,4 @@
+P=? [ F one ]
+P=? [ F two ]
+P=? [ F three ]
+R=? [ F done ]