diff --git a/Week 5/9 Ordinary Differential Equations.ipynb b/Week 5/9 Ordinary Differential Equations.ipynb
index c9eee81..4866df5 100644
--- a/Week 5/9 Ordinary Differential Equations.ipynb	
+++ b/Week 5/9 Ordinary Differential Equations.ipynb	
@@ -139,21 +139,22 @@
    "source": [
     "def integrator(x, y0, f, phi):\n",
     "    \"\"\"\n",
-    "    Numerically solves the initial value problem given by ordinary differential equation\n",
-    "    f(x, y) = y' with initial value y0 using the integration scheme provided by phi.\n",
+    "    Numerically solves the initial value problem (IVP) given by ordinary differential\n",
+    "    equation (ODE) f(x, y) = y' with initial value y0 using the integration scheme\n",
+    "    provided by phi.\n",
     "\n",
     "    Args:\n",
     "        x:   size n + 1 numerical array\n",
     "        y0:  an initial value to the function f\n",
     "        f:   a callable function with signature (x, y), with x and y the current state\n",
-    "             of the system\n",
+    "             of the system, and f such that f(x, y) = y' in the ODE\n",
     "        phi: a callable function with signature (x, y, f, i), with x and y the current state\n",
     "             of the system, i the step number, and f as above, representing the integration\n",
     "             scheme to use\n",
     "\n",
     "    Returns:\n",
-    "        An n + 1 numerical array representing an approximate solution to y' = f(x, y)\n",
-    "        given initial value y0 and steps from x\n",
+    "        An n + 1 numerical array representing an approximate solution to y in y' = f(x, y)\n",
+    "        given initial value y0, steps from x, and using integration scheme phi.\n",
     "    \"\"\"\n",
     "    \n",
     "    eta    = np.zeros(len(x))\n",
@@ -187,20 +188,18 @@
    "source": [
     "def phi_euler(x, y, f, i):\n",
     "    \"\"\"\n",
-    "    Numerically solves the initial value problem given by ordinary differential equation\n",
-    "    f(x, y) = y' with initial value y0 using the Euler method.\n",
+    "    Returns the integrator phi = f(x, y) for the Euler method to solve the ODE\n",
+    "    y' = f(x, y).\n",
     "\n",
     "    Args:\n",
-    "        x: a size n + 1 numerical array\n",
-    "        y: a size n + 1 numerical array with y[0] the initial value corresponding to x[0]\n",
+    "        x: current x value for f\n",
+    "        y: current y value for f\n",
     "        f: a callable function with signature (x, y), with x and y the current state\n",
-    "           of the system\n",
-    "        i: a callable function with signature (x, y, f, i), with x and y the current state\n",
-    "           of the system, i the step number, and f as above\n",
+    "           of the system, and f such that f(x, y) = y' in the ODE\n",
+    "        i: the step number of the IVP solving algorithm (not used)\n",
     "\n",
     "    Returns:\n",
-    "        An n + 1 numerical array representing an approximate solution to y' = f(x, y)\n",
-    "        given initial value y0 and steps from x\n",
+    "        The integrator phi(x, y, f, i) = f(x, y).\n",
     "    \"\"\"\n",
     "    \n",
     "    return f(x, y)\n",
@@ -260,7 +259,7 @@
     {
      "data": {
       "text/plain": [
-       "[<matplotlib.lines.Line2D at 0x1554d71a0610>]"
+       "[<matplotlib.lines.Line2D at 0x151df36105e0>]"
       ]
      },
      "execution_count": 4,