List[Null, Null, Null, Null, Null, Null, Null, Notebook[List[Cell[CellGroupData[List[Cell["Exercise 1", "Title"], Cell[CellGroupData[List[Cell["Question", "Section"], Cell["What is a class?", "Text"], Cell[CellGroupData[List[Cell["Answer", "Subsection"], Cell["A class is a fundamental unit of modeling in Modelica, providing the structure for an object. Classes can contain equations, where the computations are performed.", "Text"]], Closed]]], Open]], Cell[CellGroupData[List[Cell["Creating a Class", "Section"], Cell[TextData[List["Create a class, ", StyleBox["Add", Rule[FontFamily, "Courier"]], ", that calculates the sum of two parameters, which are ", StyleBox["Integer", Rule[FontFamily, "Courier"]], " numbers with given values. "]], "Text"], Cell["", "ModelicaInput"], Cell[CellGroupData[List[Cell["Answer", "Subsection"], Cell[TextData[List["Since ", StyleBox["x + y = sum ", Rule[FontFamily, "Courier"]], "is an equation and not an assignment, the equation can also be written as sum", StyleBox[" = x + y ", Rule[FontFamily, "Courier"]], "without changing the meaning of the expression."]], "Text"], Cell["class Add\n  parameter Integer x = 1;\n  parameter Integer y = 2;\n  Real sum;\nequation\n  sum = x + y;\nend Add;", "ModelicaInput"], Cell[CellGroupData[List[Cell["Simulation of Add", "Subsubsection"], Cell["simulate(Add);", "ModelicaInput"], Cell[BoxData["\"<SimulationData: \\!\\(Add\\) : 2004-1-30 9:7:46.9998633 : \\!\\({0.`, 1.`}\\) : 502 data points : 1 events : 5 variables>\\n\\!\\({\\*TagBox[\\\"\[UnderBracket]derdummy\\\", HoldForm], \\*TagBox[\\\"\[UnderBracket]dummy\\\", HoldForm], \\*TagBox[\\\"sum\\\", HoldForm], \\*TagBox[\\\"x\\\", HoldForm], \\*TagBox[\\\"y\\\", HoldForm]}\\)\""], "Output"], Cell[TextData[List["When we have simulated the class ", StyleBox["Add", Rule[FontFamily, "Courier"]], ", we can look at the values of the variables at a specific point in time by writing: variablaName[time]."]], "Text"], Cell[BoxData[RowBox[List["{", RowBox[List[RowBox[List["sum", "[", "0", "]"]], ",", " ", RowBox[List["x", "[", "0", "]"]], ",", " ", RowBox[List["y", "[", "0", "]"]]]], "}"]]], "Input"]], Closed]]], Closed]]], Open]]], Open]]], Rule[FrontEndVersion, "5.1 for Microsoft Windows"], Rule[ScreenRectangle, List[List[0, 1280], List[0, 951]]], Rule[WindowSize, List[754, 924]], Rule[WindowMargins, List[List[193, Automatic], List[Automatic, 0]]], Rule[StyleDefinitions, "MathModelica.nb"]], Null, Null, Null, Null, Null]