added multi-letter example to mathtext tutorial (#15267)

javad94 · ImportanceOfBeingErnest · commit bb7e4419001e · 2019-09-15T15:19:23.000+02:00
added multi-letter example to mathtext tutorial
diff --git a/tutorials/text/mathtext.py b/tutorials/text/mathtext.py
@@ -66,6 +66,15 @@
 
     \alpha_i > \beta_i
 
+To display multi-letter subscripts or superscripts correctly,
+you should put them in curly braces ``{...}``::
+
+    r'$\alpha^{ic} > \beta_{ic}$'
+
+.. math::
+
+    \alpha^{ic} > \beta_{ic}
+
 Some symbols automatically put their sub/superscripts under and over the
 operator.  For example, to write the sum of :mathmpl:`x_i` from :mathmpl:`0` to
 :mathmpl:`\infty`, you could do::
