diff --git a/cgp/cartesian_graph.py b/cgp/cartesian_graph.py
index afde532e..0c48bbaf 100644
--- a/cgp/cartesian_graph.py
+++ b/cgp/cartesian_graph.py
@@ -243,7 +243,7 @@ def to_func(self) -> Callable[..., List[float]]:
 
         Returns
         -------
-        Callable or Tuple[Callable]
+        Callable
 
         """
         self._format_output_str_of_all_nodes()
@@ -317,7 +317,8 @@ def to_torch(self) -> "torch.nn.Module":
         this graph.
 
         The generated instance will have a `forward` method accepting
-        Torch tensor and returning a tensor.
+        Torch tensor of dimension (<batch size>, n_inputs) and
+        returning a tensor of dimension (<batch_size>, n_outputs).
 
         Returns
         -------
@@ -382,9 +383,12 @@ def _format_output_str_sympy_of_all_nodes(self):
     def to_sympy(
         self, simplify: Optional[bool] = True
     ) -> Union["sympy_expr.Expr", List["sympy_expr.Expr"]]:
-        """Compile the function(s) represented by the graph to a SymPy expression.
+        """Create SymPy expression(s) representing the function(s) described
+        by this graph.
 
-        Generates one SymPy expression for each output node.
+        Returns a list of SymPy expressions, one for each output
+        node. For convenience, if only one output node is defined, it
+        directly returns its expression.
 
         Parameters
         ----------
@@ -394,8 +398,9 @@ def to_sympy(
 
         Returns
         ----------
-        List[sympy.core.expr.Expr]
-            List of SymPy expressions.
+        List[sympy.core.expr.Expr] or sympy.core.expr.Expr
+            List of SymPy expressions or single expression.
+
         """
 
         def possibly_unpack(