diff --git a/poincare/include/poincare/function.h b/poincare/include/poincare/function.h
index a41a9e44c..fc217e225 100644
--- a/poincare/include/poincare/function.h
+++ b/poincare/include/poincare/function.h
@@ -10,14 +10,15 @@ class Function : public Expression {
 public:
   Function(const char * name);
   ~Function();
-  void setArgument(Expression * arg, bool clone = true);
+  void setArgument(Expression ** args, int numberOfArguments, bool clone = true);
   ExpressionLayout * createLayout() const override;
   const Expression * operand(int i) const override;
   int numberOfOperands() const override;
   Expression * clone() const override;
   Expression * evaluate(Context& context) const override;
 protected:
-  const Expression * m_arg;
+  Expression ** m_args;
+  int m_numberOfArguments;
 private:
   const char * m_name;
 };
diff --git a/poincare/src/absolute_value.cpp b/poincare/src/absolute_value.cpp
index 461d4522d..e3ec1410a 100644
--- a/poincare/src/absolute_value.cpp
+++ b/poincare/src/absolute_value.cpp
@@ -18,11 +18,11 @@ Expression * AbsoluteValue::cloneWithDifferentOperands(Expression** newOperands,
         int numberOfOperands, bool cloneOperands) const {
   assert(numberOfOperands == 1);
   assert(newOperands != nullptr);
-  AbsoluteValue * c = new AbsoluteValue();
-  c->setArgument(*newOperands, cloneOperands);
-  return c;
+  AbsoluteValue * a = new AbsoluteValue();
+  a->setArgument(newOperands, numberOfOperands, cloneOperands);
+  return a;
 }
 
 float AbsoluteValue::approximate(Context& context) const {
-  return fabsf(m_arg->approximate(context));
+  return fabsf(m_args[0]->approximate(context));
 }
diff --git a/poincare/src/cosine.cpp b/poincare/src/cosine.cpp
index 9f96e0029..5aebf641d 100644
--- a/poincare/src/cosine.cpp
+++ b/poincare/src/cosine.cpp
@@ -19,10 +19,10 @@ Expression * Cosine::cloneWithDifferentOperands(Expression** newOperands,
   assert(numberOfOperands == 1);
   assert(newOperands != nullptr);
   Cosine * c = new Cosine();
-  c->setArgument(*newOperands, cloneOperands);
+  c->setArgument(newOperands, numberOfOperands, cloneOperands);
   return c;
 }
 
 float Cosine::approximate(Context& context) const {
-  return cosf(m_arg->approximate(context));
+  return cosf(m_args[0]->approximate(context));
 }
diff --git a/poincare/src/expression_parser.y b/poincare/src/expression_parser.y
index c5d04185e..a59be95e9 100644
--- a/poincare/src/expression_parser.y
+++ b/poincare/src/expression_parser.y
@@ -121,7 +121,7 @@ exp:
   | exp POW exp      { Expression * terms[2] = {$1,$3}; $$ = new Power(terms, false); }
   | LEFT_PARENTHESIS exp RIGHT_PARENTHESIS     { $$ = new Parenthesis($2, false); }
   | LEFT_BRACKET mtxData RIGHT_BRACKET { $$ = new Matrix($2); }
-  | FUNCTION LEFT_PARENTHESIS exp RIGHT_PARENTHESIS { $$ = $1; $1->setArgument($3, false); }
+  | FUNCTION LEFT_PARENTHESIS exp RIGHT_PARENTHESIS { $$ = $1; Expression * terms[1] = {$3}; $1->setArgument(terms, 1, false); }
 ;
 
 %%
diff --git a/poincare/src/function.cpp b/poincare/src/function.cpp
index d77802521..884573a37 100644
--- a/poincare/src/function.cpp
+++ b/poincare/src/function.cpp
@@ -8,48 +8,65 @@ extern "C" {
 #include "layout/string_layout.h"
 
 Function::Function(const char * name) :
-  m_arg(nullptr),
+  m_args(nullptr),
+  m_numberOfArguments(0),
   m_name(name)
 {
 }
 
-void Function::setArgument(Expression * arg, bool clone) {
-  if (m_arg != nullptr) {
-    delete m_arg;
+void Function::setArgument(Expression ** args, int numberOfArguments, bool clone) {
+  if (m_args != nullptr) {
+    for (int i = 0; i < m_numberOfArguments; i++) {
+      delete m_args[i];
+    }
+    free(m_args);
   }
-  if (clone) {
-    m_arg = arg->clone();
-  } else {
-    m_arg = arg;
+  m_numberOfArguments = numberOfArguments;
+  m_args = (Expression **)malloc(numberOfArguments*sizeof(Expression *));
+  for (int i = 0; i < numberOfArguments; i++) {
+    assert(args[i] != nullptr);
+    if (clone) {
+      m_args[i] = args[i]->clone();
+    } else {
+      m_args[i] = args[i];
+    }
   }
 }
 
 Function::~Function() {
-  if (m_arg != nullptr) {
-    delete m_arg;
+  if (m_args != nullptr) {
+    for (int i = 0; i < m_numberOfArguments; i++) {
+      delete m_args[i];
+    }
+    free(m_args);
   }
 }
 
 Expression * Function::clone() const {
-  return this->cloneWithDifferentOperands((Expression**)&m_arg, 1, true);
+  return this->cloneWithDifferentOperands(m_args, m_numberOfArguments, true);
 }
 
 ExpressionLayout * Function::createLayout() const {
-  ExpressionLayout ** childrenLayouts = (ExpressionLayout **)malloc(4*sizeof(ExpressionLayout *));
+  ExpressionLayout ** childrenLayouts = (ExpressionLayout **)malloc((2*m_numberOfArguments+2)*sizeof(ExpressionLayout *));
   childrenLayouts[0] = new StringLayout(m_name, strlen(m_name));
   childrenLayouts[1] = new StringLayout("(", 1);
-  childrenLayouts[2] = m_arg->createLayout();
-  childrenLayouts[3] = new StringLayout(")", 1);
-  return new HorizontalLayout(childrenLayouts, 4);
+  int layoutIndex = 2;
+  childrenLayouts[layoutIndex++] = m_args[0]->createLayout();
+  for (int i = 1; i < m_numberOfArguments; i++) {
+    childrenLayouts[layoutIndex++] = new StringLayout(",", 1);
+    childrenLayouts[layoutIndex++] = m_args[i]->createLayout();
+  }
+  childrenLayouts[layoutIndex] = new StringLayout(")", 1);
+  return new HorizontalLayout(childrenLayouts, 2*m_numberOfArguments+2);
 }
 
 const Expression * Function::operand(int i) const {
-  assert(i==0);
-  return m_arg;
+  assert(i >= 0 && i < m_numberOfArguments);
+  return m_args[i];
 }
 
 int Function::numberOfOperands() const {
-  return 1;
+  return m_numberOfArguments;
 }
 
 Expression * Function::evaluate(Context& context) const {
diff --git a/poincare/src/logarithm.cpp b/poincare/src/logarithm.cpp
index e4040a00b..67776cfe5 100644
--- a/poincare/src/logarithm.cpp
+++ b/poincare/src/logarithm.cpp
@@ -17,11 +17,11 @@ Expression * Logarithm::cloneWithDifferentOperands(Expression** newOperands,
         int numberOfOperands, bool cloneOperands) const {
   assert(numberOfOperands == 1);
   assert(newOperands != nullptr);
-  Logarithm * c = new Logarithm();
-  c->setArgument(*newOperands, cloneOperands);
-  return c;
+  Logarithm * l = new Logarithm();
+  l->setArgument(newOperands, numberOfOperands, cloneOperands);
+  return l;
 }
 
 float Logarithm::approximate(Context& context) const {
-  return log10f(m_arg->approximate(context));
+  return log10f(m_args[0]->approximate(context));
 }
diff --git a/poincare/src/sine.cpp b/poincare/src/sine.cpp
index 2bd97dd34..2975d2e82 100644
--- a/poincare/src/sine.cpp
+++ b/poincare/src/sine.cpp
@@ -15,7 +15,7 @@ Expression * Sine::cloneWithDifferentOperands(Expression** newOperands,
   assert(newOperands != nullptr);
   assert(numberOfOperands == 1);
   Sine * s = new Sine();
-  s->setArgument(*newOperands, cloneOperands);
+  s->setArgument(newOperands, numberOfOperands, cloneOperands);
   return s;
 }
 
@@ -24,5 +24,5 @@ Expression::Type Sine::type() const {
 }
 
 float Sine::approximate(Context& context) const {
-  return sinf(m_arg->approximate(context));
+  return sinf(m_args[0]->approximate(context));
 }
diff --git a/poincare/src/tangent.cpp b/poincare/src/tangent.cpp
index 5395b1cee..7495c3161 100644
--- a/poincare/src/tangent.cpp
+++ b/poincare/src/tangent.cpp
@@ -15,7 +15,7 @@ Expression * Tangent::cloneWithDifferentOperands(Expression** newOperands,
   assert(newOperands != nullptr);
   assert(numberOfOperands == 1);
   Tangent * t = new Tangent();
-  t->setArgument(*newOperands, cloneOperands);
+  t->setArgument(newOperands, numberOfOperands, cloneOperands);
   return t;
 }
 
@@ -24,5 +24,5 @@ Expression::Type Tangent::type() const {
 }
 
 float Tangent::approximate(Context& context) const {
-  return tanf(m_arg->approximate(context));
+  return tanf(m_args[0]->approximate(context));
 }