Fixed typos

examples/optimisation/first-example.ipynb

@@ -115,9 +115,9 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "Anything that can be made to fit the [ErrorMeasure](https://pints.readthedocs.io/en/stable/error_measures.html#pints.ErrorMeasure) interface can be optimised this way, including error measures that run simulations, make calls to other software packages, or even other languages.\n",
+    "Anything that can be made to fit the [ErrorMeasure](https://pints.readthedocs.io/en/stable/error_measures.html#pints.ErrorMeasure) interface can be optimised this way, including error measures that run simulations, make calls to other software packages, or even interface with other languages.\n",
     "\n",
-    "If you are interested in _time-series models_, you can implement PINTS `ForwardModel` interface instead, as is shown below."
+    "But if you are interested in _time-series models_, you can use PINTS `ForwardModel` and `Problem` interfaces to define your optimisation problem instead, as shown below."
    ]
   },
   {
@@ -126,7 +126,7 @@
    "source": [
     "## Fitting time-series models\n",
     "\n",
-    "To fit time-series models, we start by defining a Model by implementing the [pints.ForwardModel interface](http://pints.readthedocs.io/en/latest/core_classes_and_methods.html#forward-model).\n",
+    "To fit time-series models, we start by defining a Model that implements the [pints.ForwardModel interface](http://pints.readthedocs.io/en/latest/core_classes_and_methods.html#forward-model).\n",
     "\n",
     "As with the error function above, there are only two main methods: One to tell the optimiser how many parameters the are, and one to run the simulations.\n",
     "\n",