TL: attempt to fix mathjax rendering

Author: tlunet

docs/notebooks/14_phiIntegrator.ipynb

@@ -45,25 +45,25 @@
     "and put it in the Picard equation above to get :\n",
     "\n",
     "$$\n",
-    "\\begin{align}\n",
+    "\\begin{aligned}\n",
     "e^{k}(t) + u^{k}(t) \n",
     "    &= e^{k}(t_0) + u^{k}(t_0) + \\int_{t_0}^t f\\left(e^{k}(s) - u^{k}(s), s\\right) ds \\\\\n",
     "    &= u_0 + \\int_{t_0}^t f\\left(e^{k}(s) + u^{k}(s), s\\right) ds.\n",
-    "\\end{align}\n",
+    "\\end{aligned}\n",
     "$$\n",
     "\n",
     "Noting \n",
     "$u^{k+1}(t) := e^{k}(t) + u^{k}(t)$\n",
     "and adding the difference of the two same integral terms with $u^{k}$ we get :\n",
     "\n",
     "$$\n",
-    "\\begin{align}\n",
+    "\\begin{aligned}\n",
     "u^{k+1}(t) \n",
     "    =&~ u_0 + \\int_{t_0}^t f\\left(u^{k+1}(s), s\\right) ds \\\\\n",
     "    &- \\int_{t_0}^t f\\left(u^{k}(s), s\\right) ds + \\int_{t_0}^t f\\left(u^{k}(s), s\\right) ds \\\\\n",
     "    =&~ u_0 + \\int_{t_0}^t f\\left(u^{k+1}(s), s\\right) ds - \\int_{t_0}^t f\\left(u^{k}(s), s\\right) ds \\\\\n",
     "    &+ \\int_{t_0}^t f\\left(u^{k}(s), s\\right) ds\n",
-    "\\end{align}\n",
+    "\\end{aligned}\n",
     "$$\n",
     "\n",
     "$\\phi$**-based Spectral Deferred Correction** : \n",