From 7ffe322e06e46595cb337a47d5b8b6dd2a4c9434 Mon Sep 17 00:00:00 2001
From: Tim Quatmann <tim.quatmann@cs.rwth-aachen.de>
Date: Wed, 8 Apr 2020 12:31:45 +0200
Subject: [PATCH] SparseModelMemoryProduct: Fixed incorrect computation of
 state-action rewards under a randomized policy.

---
 src/storm/storage/memorystructure/SparseModelMemoryProduct.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/storm/storage/memorystructure/SparseModelMemoryProduct.cpp b/src/storm/storage/memorystructure/SparseModelMemoryProduct.cpp
index 3907f0625..1f30f23fb 100644
--- a/src/storm/storage/memorystructure/SparseModelMemoryProduct.cpp
+++ b/src/storm/storage/memorystructure/SparseModelMemoryProduct.cpp
@@ -410,7 +410,7 @@ namespace storm {
                                 if (isStateReachable(modelState, memoryState)) {
                                     if (scheduler && scheduler->getChoice(modelState, memoryState).isDefined()) {
                                         ValueType factor = scheduler->getChoice(modelState, memoryState).getChoiceAsDistribution().getProbability(rowOffset);
-                                        stateActionRewards.get()[resultTransitionMatrix.getRowGroupIndices()[getResultState(modelState, memoryState)]] = factor * modelStateActionReward;
+                                        stateActionRewards.get()[resultTransitionMatrix.getRowGroupIndices()[getResultState(modelState, memoryState)]] += factor * modelStateActionReward;
                                     } else {
                                         stateActionRewards.get()[resultTransitionMatrix.getRowGroupIndices()[getResultState(modelState, memoryState)] + rowOffset] = modelStateActionReward;
                                     }