diff --git a/poincare/include/poincare.h b/poincare/include/poincare.h
index 9fd9495dc..6b6564474 100644
--- a/poincare/include/poincare.h
+++ b/poincare/include/poincare.h
@@ -1,6 +1,8 @@
 #ifndef POINCARE_H
 #define POINCARE_H
 
+#define MATRICES_ARE_DEFINED 1
+
 #include <poincare/absolute_value.h>
 #include <poincare/addition.h>
 #include <poincare/arc_cosine.h>
diff --git a/poincare/test/parser.cpp b/poincare/test/parser.cpp
index 5e46e6505..f5d0d3f81 100644
--- a/poincare/test/parser.cpp
+++ b/poincare/test/parser.cpp
@@ -6,36 +6,40 @@
 
 using namespace Poincare;
 
+constexpr Expression::AngleUnit Degree = Expression::AngleUnit::Degree;
+constexpr Expression::AngleUnit Radian = Expression::AngleUnit::Radian;
+
+void assert_expression_parses_to(const char * text, float result, Context * context, Expression::AngleUnit angleUnit = Degree) {
+  char buffer_text[100] = {};
+  for (int i=0; i<strlen(text); i++) {
+    buffer_text[i] = text[i];
+    if (text[i] == 'E') {
+      buffer_text[i] = Ion::Charset::Exponent;
+    }
+    if (text[i] == 'e') {
+      buffer_text[i] = Ion::Charset::Exponential;
+    }
+    if (text[i] == 'I') {
+      buffer_text[i] = Ion::Charset::IComplex;
+    }
+  }
+  Expression * a = Expression::parse(buffer_text);
+  assert(fabsf(a->approximate(*context, angleUnit) - result) < 0.0001f);
+}
+
 QUIZ_CASE(poincare_parser) {
   GlobalContext globalContext;
-  char text0[10] = {'1', '.', '2', '*', Ion::Charset::Exponential, '^', '(', '1', ')', 0};
-  Expression * a = Expression::parse(text0);
-  float f =1.2f*M_E;
-  assert(a->approximate(globalContext) == f);
-
-  char text1[10] = {Ion::Charset::Exponential, '^', '2', '*', Ion::Charset::Exponential, '^', '(', '1', ')', 0};
-  a = Expression::parse(text1);
-  f = powf(M_E, 2.0f)*M_E;
-  assert(a->approximate(globalContext) == f);
-
-  a = Expression::parse("2*3^4+2");
-  f = 2.0f*powf(3.0f, 4.0f)+2.0f;
-  assert(a->approximate(globalContext) == f);
-
-  a = Expression::parse("-2*3^4+2");
-  f = -2.0f*powf(3.0f, 4.0f)+2.0f;
-  assert(a->approximate(globalContext) == f);
-
-  a = Expression::parse("-sin(3)*2-3");
-  f = -sinf(3.0f)*2.0f-3.0f;
-  assert(a->approximate(globalContext, Expression::AngleUnit::Radian) == f);
-
-  a = Expression::parse("-.003");
-  f = -0.003f;
-  assert(a->approximate(globalContext) == f);
-
-  char text2[10] = {'.', '0', '2', Ion::Charset::Exponent, '2', 0};
-  a = Expression::parse(text2);
-  f = 2.0f;
-  assert(a->approximate(globalContext) == f);
-}
\ No newline at end of file
+  assert_expression_parses_to("1.2*e^(1)", 1.2*M_E, &globalContext);
+  assert_expression_parses_to("e^2*e^(1)", powf(M_E, 2.0f)*M_E, &globalContext);
+  assert_expression_parses_to("2*3^4+2", 2.0f*powf(3.0f, 4.0f)+2.0f, &globalContext);
+  assert_expression_parses_to("-2*3^4+2", -2.0f*powf(3.0f, 4.0f)+2.0f, &globalContext);
+  assert_expression_parses_to("-sin(3)*2-3", -sinf(3.0f)*2.0f-3.0f, &globalContext, Radian);
+  assert_expression_parses_to("-.003", -0.003f, &globalContext);
+  assert_expression_parses_to(".02E2", 2.0f, &globalContext);
+  assert_expression_parses_to("5-2/3", 5.0f-2.0f/3.0f, &globalContext);
+  assert_expression_parses_to("2/3-5", 2.0f/3.0f-5.0f, &globalContext);
+  assert_expression_parses_to("-2/3-5", -2.0f/3.0f-5.0f, &globalContext);
+  assert_expression_parses_to("sin(3)2(4+2)", sinf(3.0f)*2.0f*(4.0f+2.0f), &globalContext, Radian);
+  assert_expression_parses_to("4/2*(2+3)", 4.0f/2.0f*(2.0f+3.0f), &globalContext, Radian);
+  assert_expression_parses_to("4/2*(2+3)", 4.0f/2.0f*(2.0f+3.0f), &globalContext, Radian);
+}