Topological solvers: Added a warning for numerical issues triggered in cases where in non-exact mode a selfloop probability is very close to 1 but not equal to 1

src/storm/solver/TopologicalLinearEquationSolver.cpp

@@ -144,11 +144,12 @@ namespace storm {
             }
             
             if (hasDiagonalEntry) {
-                    if (storm::utility::isZero(denominator)) {
-                        STORM_LOG_THROW(storm::utility::isZero(xi), storm::exceptions::InvalidOperationException, "The equation system has no solution.");
-                    } else {
-                        xi /= denominator;
-                    }
+                STORM_LOG_WARN_COND_DEBUG(storm::NumberTraits<ValueType>::IsExact || !storm::utility::isAlmostZero(denominator) || storm::utility::isZero(denominator), "State " << sccState << " has a selfloop with probability '1-(" << denominator << ")'. This could be an indication for numerical issues.");
+                if (storm::utility::isZero(denominator)) {
+                    STORM_LOG_THROW(storm::utility::isZero(xi), storm::exceptions::InvalidOperationException, "The equation system has no solution.");
+                } else {
+                    xi /= denominator;
+                }
             }
             return true;
         }

src/storm/solver/TopologicalMinMaxLinearEquationSolver.cpp

@@ -155,6 +155,7 @@ namespace storm {
                     }
                 }
                 if (hasDiagonalEntry) {
+                    STORM_LOG_WARN_COND_DEBUG(storm::NumberTraits<ValueType>::IsExact || !storm::utility::isAlmostZero(denominator) || storm::utility::isZero(denominator), "State " << sccState << " has a selfloop with probability '1-(" << denominator << ")'. This could be an indication for numerical issues.");
                     if (storm::utility::isZero(denominator)) {
                         // In this case we have a selfloop on this state. This can never an optimal choice:
                         // When minimizing, we are looking for the largest fixpoint (which will never be attained by this action)