diff --git a/poincare/src/absolute_value.cpp b/poincare/src/absolute_value.cpp
index dc39afeba..963fc570a 100644
--- a/poincare/src/absolute_value.cpp
+++ b/poincare/src/absolute_value.cpp
@@ -28,8 +28,8 @@ LayoutRef AbsoluteValue::createLayout(Preferences::PrintFloatMode floatDisplayMo
 }
 
 Expression AbsoluteValue::shallowReduce(Context& context, Preferences::AngleUnit angleUnit) const {
-  Expression * e = Expression::defaultShallowReduce(context, angleUnit);
-  if (e != this) {
+  Expression e = Expression::defaultShallowReduce(context, angleUnit);
+  if (e.isUndefinedOrAllocationFailure()) {
     return e;
   }
   Expression * op = editableOperand(0);
diff --git a/poincare/src/arc_sine.cpp b/poincare/src/arc_sine.cpp
index 41619b0df..48172e440 100644
--- a/poincare/src/arc_sine.cpp
+++ b/poincare/src/arc_sine.cpp
@@ -18,8 +18,8 @@ Expression * ArcSine::clone() const {
 }
 
 Expression ArcSine::shallowReduce(Context& context, Preferences::AngleUnit angleUnit) const {
-  Expression * e = Expression::defaultShallowReduce(context, angleUnit);
-  if (e != this) {
+  Expression e = Expression::defaultShallowReduce(context, angleUnit);
+  if (e.isUndefinedOrAllocationFailure()) {
     return e;
   }
 #if MATRIX_EXACT_REDUCING
diff --git a/poincare/src/arc_tangent.cpp b/poincare/src/arc_tangent.cpp
index 55fbd2f85..2bd359ffa 100644
--- a/poincare/src/arc_tangent.cpp
+++ b/poincare/src/arc_tangent.cpp
@@ -18,8 +18,8 @@ Expression * ArcTangent::clone() const {
 }
 
 Expression ArcTangent::shallowReduce(Context& context, Preferences::AngleUnit angleUnit) const {
-  Expression * e = Expression::defaultShallowReduce(context, angleUnit);
-  if (e != this) {
+  Expression e = Expression::defaultShallowReduce(context, angleUnit);
+  if (e.isUndefinedOrAllocationFailure()) {
     return e;
   }
 #if MATRIX_EXACT_REDUCING
diff --git a/poincare/src/binomial_coefficient.cpp b/poincare/src/binomial_coefficient.cpp
index 0cf02ec11..54053b2a3 100644
--- a/poincare/src/binomial_coefficient.cpp
+++ b/poincare/src/binomial_coefficient.cpp
@@ -21,8 +21,8 @@ Expression * BinomialCoefficient::clone() const {
 }
 
 Expression BinomialCoefficient::shallowReduce(Context& context, Preferences::AngleUnit angleUnit) const {
-  Expression * e = Expression::defaultShallowReduce(context, angleUnit);
-  if (e != this) {
+  Expression e = Expression::defaultShallowReduce(context, angleUnit);
+  if (e.isUndefinedOrAllocationFailure()) {
     return e;
   }
   Expression * op0 = editableOperand(0);
diff --git a/poincare/src/ceiling.cpp b/poincare/src/ceiling.cpp
index 1bb2e52d6..41f1cd654 100644
--- a/poincare/src/ceiling.cpp
+++ b/poincare/src/ceiling.cpp
@@ -21,8 +21,8 @@ Expression * Ceiling::clone() const {
 }
 
 Expression Ceiling::shallowReduce(Context& context, Preferences::AngleUnit angleUnit) const {
-  Expression * e = Expression::defaultShallowReduce(context, angleUnit);
-  if (e != this) {
+  Expression e = Expression::defaultShallowReduce(context, angleUnit);
+  if (e.isUndefinedOrAllocationFailure()) {
     return e;
   }
   Expression * op = editableOperand(0);
diff --git a/poincare/src/complex_argument.cpp b/poincare/src/complex_argument.cpp
index dbe15c412..cea8571ad 100644
--- a/poincare/src/complex_argument.cpp
+++ b/poincare/src/complex_argument.cpp
@@ -17,8 +17,8 @@ Expression * ComplexArgument::clone() const {
 }
 
 Expression ComplexArgument::shallowReduce(Context& context, Preferences::AngleUnit angleUnit) const {
-  Expression * e = Expression::defaultShallowReduce(context, angleUnit);
-  if (e != this) {
+  Expression e = Expression::defaultShallowReduce(context, angleUnit);
+  if (e.isUndefinedOrAllocationFailure()) {
     return e;
   }
 #if MATRIX_EXACT_REDUCING
diff --git a/poincare/src/confidence_interval.cpp b/poincare/src/confidence_interval.cpp
index 44b192c87..edaedc0d5 100644
--- a/poincare/src/confidence_interval.cpp
+++ b/poincare/src/confidence_interval.cpp
@@ -25,8 +25,8 @@ int ConfidenceInterval::polynomialDegree(char symbolName) const {
 }
 
 Expression ConfidenceInterval::shallowReduce(Context& context, Preferences::AngleUnit angleUnit) const {
-  Expression * e = Expression::defaultShallowReduce(context, angleUnit);
-  if (e != this) {
+  Expression e = Expression::defaultShallowReduce(context, angleUnit);
+  if (e.isUndefinedOrAllocationFailure()) {
     return e;
   }
   Expression * op0 = editableOperand(0);
diff --git a/poincare/src/conjugate.cpp b/poincare/src/conjugate.cpp
index e29c9b54e..e09000577 100644
--- a/poincare/src/conjugate.cpp
+++ b/poincare/src/conjugate.cpp
@@ -20,8 +20,8 @@ LayoutRef Conjugate::createLayout(Preferences::PrintFloatMode floatDisplayMode,
 }
 
 Expression Conjugate::shallowReduce(Context& context, Preferences::AngleUnit angleUnit) const {
-  Expression * e = Expression::defaultShallowReduce(context, angleUnit);
-  if (e != this) {
+  Expression e = Expression::defaultShallowReduce(context, angleUnit);
+  if (e.isUndefinedOrAllocationFailure()) {
     return e;
   }
   Expression * op = editableOperand(0);
diff --git a/poincare/src/determinant.cpp b/poincare/src/determinant.cpp
index 901a35546..4c4420f37 100644
--- a/poincare/src/determinant.cpp
+++ b/poincare/src/determinant.cpp
@@ -17,8 +17,8 @@ Expression * Determinant::clone() const {
 }
 
 Expression Determinant::shallowReduce(Context& context, Preferences::AngleUnit angleUnit) const {
-  Expression * e = Expression::defaultShallowReduce(context, angleUnit);
-  if (e != this) {
+  Expression e = Expression::defaultShallowReduce(context, angleUnit);
+  if (e.isUndefinedOrAllocationFailure()) {
     return e;
   }
   Expression * op = editableOperand(0);
diff --git a/poincare/src/division_quotient.cpp b/poincare/src/division_quotient.cpp
index bbfddc129..f38e2fa57 100644
--- a/poincare/src/division_quotient.cpp
+++ b/poincare/src/division_quotient.cpp
@@ -19,8 +19,8 @@ Expression * DivisionQuotient::clone() const {
 }
 
 Expression DivisionQuotient::shallowReduce(Context& context, Preferences::AngleUnit angleUnit) const {
-  Expression * e = Expression::defaultShallowReduce(context, angleUnit);
-  if (e != this) {
+  Expression e = Expression::defaultShallowReduce(context, angleUnit);
+  if (e.isUndefinedOrAllocationFailure()) {
     return e;
   }
   Expression * op0 = editableOperand(0);
diff --git a/poincare/src/division_remainder.cpp b/poincare/src/division_remainder.cpp
index 10cadf344..94949ffa8 100644
--- a/poincare/src/division_remainder.cpp
+++ b/poincare/src/division_remainder.cpp
@@ -19,8 +19,8 @@ Expression * DivisionRemainder::clone() const {
 }
 
 Expression DivisionRemainder::shallowReduce(Context& context, Preferences::AngleUnit angleUnit) const {
-  Expression * e = Expression::defaultShallowReduce(context, angleUnit);
-  if (e != this) {
+  Expression e = Expression::defaultShallowReduce(context, angleUnit);
+  if (e.isUndefinedOrAllocationFailure()) {
     return e;
   }
   Expression * op0 = editableOperand(0);
diff --git a/poincare/src/equal.cpp b/poincare/src/equal.cpp
index 5c5c47835..efd59d546 100644
--- a/poincare/src/equal.cpp
+++ b/poincare/src/equal.cpp
@@ -39,8 +39,8 @@ Expression * Equal::standardEquation(Context & context, Preferences::AngleUnit a
 }
 
 Expression Equal::shallowReduce(Context& context, Preferences::AngleUnit angleUnit) const {
-  Expression * e = Expression::defaultShallowReduce(context, angleUnit);
-  if (e != this) {
+  Expression e = Expression::defaultShallowReduce(context, angleUnit);
+  if (e.isUndefinedOrAllocationFailure()) {
     return e;
   }
   if (operand(0)->isIdenticalTo(operand(1))) {
diff --git a/poincare/src/factorial.cpp b/poincare/src/factorial.cpp
index 5b8f4b7af..618235e18 100644
--- a/poincare/src/factorial.cpp
+++ b/poincare/src/factorial.cpp
@@ -37,8 +37,8 @@ bool Factorial::needsParenthesesWithParent(const SerializationHelperInterface *
 /* Simplification */
 
 Expression Factorial::shallowReduce(Context& context, Preferences::AngleUnit angleUnit) const {
-  Expression * e = Expression::defaultShallowReduce(context, angleUnit);
-  if (e != this) {
+  Expression e = Expression::defaultShallowReduce(context, angleUnit);
+  if (e.isUndefinedOrAllocationFailure()) {
     return e;
   }
 #if MATRIX_EXACT_REDUCING
diff --git a/poincare/src/floor.cpp b/poincare/src/floor.cpp
index 074846278..6336fdd5a 100644
--- a/poincare/src/floor.cpp
+++ b/poincare/src/floor.cpp
@@ -21,8 +21,8 @@ Expression * Floor::clone() const {
 }
 
 Expression Floor::shallowReduce(Context& context, Preferences::AngleUnit angleUnit) const {
-  Expression * e = Expression::defaultShallowReduce(context, angleUnit);
-  if (e != this) {
+  Expression e = Expression::defaultShallowReduce(context, angleUnit);
+  if (e.isUndefinedOrAllocationFailure()) {
     return e;
   }
   Expression * op = editableOperand(0);
diff --git a/poincare/src/frac_part.cpp b/poincare/src/frac_part.cpp
index 92c444347..397ee7418 100644
--- a/poincare/src/frac_part.cpp
+++ b/poincare/src/frac_part.cpp
@@ -18,8 +18,8 @@ Expression * FracPart::clone() const {
 }
 
 Expression FracPart::shallowReduce(Context& context, Preferences::AngleUnit angleUnit) const {
-  Expression * e = Expression::defaultShallowReduce(context, angleUnit);
-  if (e != this) {
+  Expression e = Expression::defaultShallowReduce(context, angleUnit);
+  if (e.isUndefinedOrAllocationFailure()) {
     return e;
   }
   Expression * op = editableOperand(0);
diff --git a/poincare/src/great_common_divisor.cpp b/poincare/src/great_common_divisor.cpp
index 4837b5b13..d901d12ee 100644
--- a/poincare/src/great_common_divisor.cpp
+++ b/poincare/src/great_common_divisor.cpp
@@ -20,8 +20,8 @@ Expression * GreatCommonDivisor::clone() const {
 }
 
 Expression GreatCommonDivisor::shallowReduce(Context& context, Preferences::AngleUnit angleUnit) const {
-  Expression * e = Expression::defaultShallowReduce(context, angleUnit);
-  if (e != this) {
+  Expression e = Expression::defaultShallowReduce(context, angleUnit);
+  if (e.isUndefinedOrAllocationFailure()) {
     return e;
   }
   Expression * op0 = editableOperand(0);
diff --git a/poincare/src/hyperbolic_arc_cosine.cpp b/poincare/src/hyperbolic_arc_cosine.cpp
index 750d9e86f..5ce61e7f2 100644
--- a/poincare/src/hyperbolic_arc_cosine.cpp
+++ b/poincare/src/hyperbolic_arc_cosine.cpp
@@ -18,8 +18,8 @@ Expression * HyperbolicArcCosine::clone() const {
 }
 
 Expression HyperbolicArcCosine::shallowReduce(Context& context, Preferences::AngleUnit angleUnit) const {
-  Expression * e = Expression::defaultShallowReduce(context, angleUnit);
-  if (e != this) {
+  Expression e = Expression::defaultShallowReduce(context, angleUnit);
+  if (e.isUndefinedOrAllocationFailure()) {
     return e;
   }
 #if MATRIX_EXACT_REDUCING
diff --git a/poincare/src/hyperbolic_arc_sine.cpp b/poincare/src/hyperbolic_arc_sine.cpp
index 7bee6bde6..6351ee67d 100644
--- a/poincare/src/hyperbolic_arc_sine.cpp
+++ b/poincare/src/hyperbolic_arc_sine.cpp
@@ -18,8 +18,8 @@ Expression * HyperbolicArcSine::clone() const {
 }
 
 Expression HyperbolicArcSine::shallowReduce(Context& context, Preferences::AngleUnit angleUnit) const {
-  Expression * e = Expression::defaultShallowReduce(context, angleUnit);
-  if (e != this) {
+  Expression e = Expression::defaultShallowReduce(context, angleUnit);
+  if (e.isUndefinedOrAllocationFailure()) {
     return e;
   }
 #if MATRIX_EXACT_REDUCING
diff --git a/poincare/src/hyperbolic_arc_tangent.cpp b/poincare/src/hyperbolic_arc_tangent.cpp
index 539ff09e8..1752b7d36 100644
--- a/poincare/src/hyperbolic_arc_tangent.cpp
+++ b/poincare/src/hyperbolic_arc_tangent.cpp
@@ -18,8 +18,8 @@ Expression * HyperbolicArcTangent::clone() const {
 }
 
 Expression HyperbolicArcTangent::shallowReduce(Context& context, Preferences::AngleUnit angleUnit) const {
-  Expression * e = Expression::defaultShallowReduce(context, angleUnit);
-  if (e != this) {
+  Expression e = Expression::defaultShallowReduce(context, angleUnit);
+  if (e.isUndefinedOrAllocationFailure()) {
     return e;
   }
 #if MATRIX_EXACT_REDUCING
diff --git a/poincare/src/hyperbolic_cosine.cpp b/poincare/src/hyperbolic_cosine.cpp
index 27ed1ffac..be1f400b5 100644
--- a/poincare/src/hyperbolic_cosine.cpp
+++ b/poincare/src/hyperbolic_cosine.cpp
@@ -22,8 +22,8 @@ Expression * HyperbolicCosine::clone() const {
 }
 
 Expression HyperbolicCosine::shallowReduce(Context& context, Preferences::AngleUnit angleUnit) const {
-  Expression * e = Expression::defaultShallowReduce(context, angleUnit);
-  if (e != this) {
+  Expression e = Expression::defaultShallowReduce(context, angleUnit);
+  if (e.isUndefinedOrAllocationFailure()) {
     return e;
   }
 #if MATRIX_EXACT_REDUCING
diff --git a/poincare/src/hyperbolic_sine.cpp b/poincare/src/hyperbolic_sine.cpp
index d98bcd246..2cd2a8218 100644
--- a/poincare/src/hyperbolic_sine.cpp
+++ b/poincare/src/hyperbolic_sine.cpp
@@ -22,8 +22,8 @@ Expression * HyperbolicSine::clone() const {
 }
 
 Expression HyperbolicSine::shallowReduce(Context& context, Preferences::AngleUnit angleUnit) const {
-  Expression * e = Expression::defaultShallowReduce(context, angleUnit);
-  if (e != this) {
+  Expression e = Expression::defaultShallowReduce(context, angleUnit);
+  if (e.isUndefinedOrAllocationFailure()) {
     return e;
   }
 #if MATRIX_EXACT_REDUCING
diff --git a/poincare/src/hyperbolic_tangent.cpp b/poincare/src/hyperbolic_tangent.cpp
index ca2fdf6bc..370f5946e 100644
--- a/poincare/src/hyperbolic_tangent.cpp
+++ b/poincare/src/hyperbolic_tangent.cpp
@@ -21,8 +21,8 @@ Expression * HyperbolicTangent::clone() const {
 }
 
 Expression HyperbolicTangent::shallowReduce(Context& context, Preferences::AngleUnit angleUnit) const {
-  Expression * e = Expression::defaultShallowReduce(context, angleUnit);
-  if (e != this) {
+  Expression e = Expression::defaultShallowReduce(context, angleUnit);
+  if (e.isUndefinedOrAllocationFailure()) {
     return e;
   }
 #if MATRIX_EXACT_REDUCING
diff --git a/poincare/src/imaginary_part.cpp b/poincare/src/imaginary_part.cpp
index 6fe8c9326..00b747ff5 100644
--- a/poincare/src/imaginary_part.cpp
+++ b/poincare/src/imaginary_part.cpp
@@ -19,8 +19,8 @@ Expression * ImaginaryPart::clone() const {
 
 
 Expression ImaginaryPart::shallowReduce(Context& context, Preferences::AngleUnit angleUnit) const {
-  Expression * e = Expression::defaultShallowReduce(context, angleUnit);
-  if (e != this) {
+  Expression e = Expression::defaultShallowReduce(context, angleUnit);
+  if (e.isUndefinedOrAllocationFailure()) {
     return e;
   }
   Expression * op = editableOperand(0);
diff --git a/poincare/src/integral.cpp b/poincare/src/integral.cpp
index ea6f02699..da19ca6db 100644
--- a/poincare/src/integral.cpp
+++ b/poincare/src/integral.cpp
@@ -32,8 +32,8 @@ int Integral::polynomialDegree(char symbolName) const {
 }
 
 Expression Integral::shallowReduce(Context& context, Preferences::AngleUnit angleUnit) const {
-  Expression * e = Expression::defaultShallowReduce(context, angleUnit);
-  if (e != this) {
+  Expression e = Expression::defaultShallowReduce(context, angleUnit);
+  if (e.isUndefinedOrAllocationFailure()) {
     return e;
   }
 #if MATRIX_EXACT_REDUCING
diff --git a/poincare/src/least_common_multiple.cpp b/poincare/src/least_common_multiple.cpp
index f69f6ce69..6f8fa0511 100644
--- a/poincare/src/least_common_multiple.cpp
+++ b/poincare/src/least_common_multiple.cpp
@@ -20,8 +20,8 @@ Expression * LeastCommonMultiple::clone() const {
 }
 
 Expression LeastCommonMultiple::shallowReduce(Context& context, Preferences::AngleUnit angleUnit) const {
-  Expression * e = Expression::defaultShallowReduce(context, angleUnit);
-  if (e != this) {
+  Expression e = Expression::defaultShallowReduce(context, angleUnit);
+  if (e.isUndefinedOrAllocationFailure()) {
     return e;
   }
   Expression * op0 = editableOperand(0);
diff --git a/poincare/src/matrix_dimension.cpp b/poincare/src/matrix_dimension.cpp
index d938ea874..74d617f91 100644
--- a/poincare/src/matrix_dimension.cpp
+++ b/poincare/src/matrix_dimension.cpp
@@ -17,8 +17,8 @@ Expression * MatrixDimension::clone() const {
 }
 
 Expression MatrixDimension::shallowReduce(Context& context, Preferences::AngleUnit angleUnit) const {
-  Expression * e = Expression::defaultShallowReduce(context, angleUnit);
-  if (e != this) {
+  Expression e = Expression::defaultShallowReduce(context, angleUnit);
+  if (e.isUndefinedOrAllocationFailure()) {
     return e;
   }
 #if MATRIX_EXACT_REDUCING
diff --git a/poincare/src/matrix_inverse.cpp b/poincare/src/matrix_inverse.cpp
index a4a537903..a4de76750 100644
--- a/poincare/src/matrix_inverse.cpp
+++ b/poincare/src/matrix_inverse.cpp
@@ -20,8 +20,8 @@ Expression * MatrixInverse::clone() const {
 }
 
 Expression MatrixInverse::shallowReduce(Context& context, Preferences::AngleUnit angleUnit) const {
-  Expression * e = Expression::defaultShallowReduce(context, angleUnit);
-  if (e != this) {
+  Expression e = Expression::defaultShallowReduce(context, angleUnit);
+  if (e.isUndefinedOrAllocationFailure()) {
     return e;
   }
   Expression * op = editableOperand(0);
diff --git a/poincare/src/matrix_trace.cpp b/poincare/src/matrix_trace.cpp
index 37bd5bbb6..a867b2c7a 100644
--- a/poincare/src/matrix_trace.cpp
+++ b/poincare/src/matrix_trace.cpp
@@ -19,8 +19,8 @@ Expression * MatrixTrace::clone() const {
 }
 
 Expression MatrixTrace::shallowReduce(Context& context, Preferences::AngleUnit angleUnit) const {
-  Expression * e = Expression::defaultShallowReduce(context, angleUnit);
-  if (e != this) {
+  Expression e = Expression::defaultShallowReduce(context, angleUnit);
+  if (e.isUndefinedOrAllocationFailure()) {
     return e;
   }
   Expression * op = editableOperand(0);
diff --git a/poincare/src/matrix_transpose.cpp b/poincare/src/matrix_transpose.cpp
index 157a448a0..6b61866ca 100644
--- a/poincare/src/matrix_transpose.cpp
+++ b/poincare/src/matrix_transpose.cpp
@@ -18,8 +18,8 @@ Expression * MatrixTranspose::clone() const {
 }
 
 Expression MatrixTranspose::shallowReduce(Context& context, Preferences::AngleUnit angleUnit) const {
-  Expression * e = Expression::defaultShallowReduce(context, angleUnit);
-  if (e != this) {
+  Expression e = Expression::defaultShallowReduce(context, angleUnit);
+  if (e.isUndefinedOrAllocationFailure()) {
     return e;
   }
   Expression * op = editableOperand(0);
diff --git a/poincare/src/permute_coefficient.cpp b/poincare/src/permute_coefficient.cpp
index 94b04c382..1ac6e9331 100644
--- a/poincare/src/permute_coefficient.cpp
+++ b/poincare/src/permute_coefficient.cpp
@@ -19,8 +19,8 @@ Expression * PermuteCoefficient::clone() const {
 }
 
 Expression PermuteCoefficient::shallowReduce(Context& context, Preferences::AngleUnit angleUnit) const {
-  Expression * e = Expression::defaultShallowReduce(context, angleUnit);
-  if (e != this) {
+  Expression e = Expression::defaultShallowReduce(context, angleUnit);
+  if (e.isUndefinedOrAllocationFailure()) {
     return e;
   }
   Expression * op0 = editableOperand(0);
diff --git a/poincare/src/prediction_interval.cpp b/poincare/src/prediction_interval.cpp
index 46f400671..84e8cf422 100644
--- a/poincare/src/prediction_interval.cpp
+++ b/poincare/src/prediction_interval.cpp
@@ -26,8 +26,8 @@ int PredictionInterval::polynomialDegree(char symbolName) const {
 }
 
 Expression PredictionInterval::shallowReduce(Context& context, Preferences::AngleUnit angleUnit) const {
-  Expression * e = Expression::defaultShallowReduce(context, angleUnit);
-  if (e != this) {
+  Expression e = Expression::defaultShallowReduce(context, angleUnit);
+  if (e.isUndefinedOrAllocationFailure()) {
     return e;
   }
   Expression * op0 = editableOperand(0);
diff --git a/poincare/src/real_part.cpp b/poincare/src/real_part.cpp
index 047fc6d50..f439c828e 100644
--- a/poincare/src/real_part.cpp
+++ b/poincare/src/real_part.cpp
@@ -17,8 +17,8 @@ Expression * RealPart::clone() const {
 }
 
 Expression RealPart::shallowReduce(Context& context, Preferences::AngleUnit angleUnit) const {
-  Expression * e = Expression::defaultShallowReduce(context, angleUnit);
-  if (e != this) {
+  Expression e = Expression::defaultShallowReduce(context, angleUnit);
+  if (e.isUndefinedOrAllocationFailure()) {
     return e;
   }
   Expression * op = editableOperand(0);
diff --git a/poincare/src/round.cpp b/poincare/src/round.cpp
index a9a10f4ca..4ef980028 100644
--- a/poincare/src/round.cpp
+++ b/poincare/src/round.cpp
@@ -20,8 +20,8 @@ Expression * Round::clone() const {
 }
 
 Expression Round::shallowReduce(Context& context, Preferences::AngleUnit angleUnit) const {
-  Expression * e = Expression::defaultShallowReduce(context, angleUnit);
-  if (e != this) {
+  Expression e = Expression::defaultShallowReduce(context, angleUnit);
+  if (e.isUndefinedOrAllocationFailure()) {
     return e;
   }
 #if MATRIX_EXACT_REDUCING