diff --git a/ortools/linear_solver/sat_proto_solver.h b/ortools/linear_solver/sat_proto_solver.h
new file mode 100644
index 0000000000..87b037b942
--- /dev/null
+++ b/ortools/linear_solver/sat_proto_solver.h
@@ -0,0 +1,28 @@
+// Copyright 2010-2018 Google LLC
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef OR_TOOLS_LINEAR_SOLVER_SAT_PROTO_SOLVER_H_
+#define OR_TOOLS_LINEAR_SOLVER_SAT_PROTO_SOLVER_H_
+
+#include "ortools/base/statusor.h"
+#include "ortools/linear_solver/linear_solver.pb.h"
+
+namespace operations_research {
+
+// If possible, std::move the request into this function call to avoid a copy.
+util::StatusOr<MPSolutionResponse> SatSolveProto(
+    MPModelRequest request, std::atomic<bool>* interrupt_solve = nullptr);
+
+}  // namespace operations_research
+
+#endif  // OR_TOOLS_LINEAR_SOLVER_SAT_PROTO_SOLVER_H_
diff --git a/ortools/sat/implied_bounds.h b/ortools/sat/implied_bounds.h
index 1e68997475..4b219ebfd3 100644
--- a/ortools/sat/implied_bounds.h
+++ b/ortools/sat/implied_bounds.h
@@ -40,8 +40,8 @@ struct ImpliedBoundEntry {
   // An integer variable in [0, 1]. When at 1, then the IntegerVariable
   // corresponding to this entry must be greater or equal to the given lower
   // bound.
-  IntegerVariable literal_view;
-  IntegerValue lower_bound;
+  IntegerVariable literal_view = kNoIntegerVariable;
+  IntegerValue lower_bound = IntegerValue(0);
 
   // If false, it is when the literal_view is zero that the lower bound is
   // valid.
@@ -52,7 +52,7 @@ struct ImpliedBoundEntry {
       : literal_view(lit), lower_bound(lb), is_positive(pos) {}
 
   ImpliedBoundEntry()
-      : literal_view(kNoIntegerVariable), lower_bound(0), is_positive(false) {}
+      : literal_view(kNoIntegerVariable), lower_bound(0), is_positive(true) {}
 };
 
 // Maintains all the implications of the form Literal => IntegerLiteral. We