Typo fixing.

source/algorithms/deutsch.rst

@@ -151,7 +151,7 @@ mapped as shown below.
 
 .. admonition:: XOR encoding of boolean functions
 
-    F(x_1, x_2, \ldots, x_n, z) = (x_1, x_2, \ldots, x_n, z \oplus f(x_1, x_2, \ldots, x_n))
+    :math:`F(x_1, x_2, \ldots, x_n, z) = (x_1, x_2, \ldots, x_n, z \oplus f(x_1, x_2, \ldots, x_n))`
 
 
 So we have transformed our classical function into a new function that takes booleans and returns a pair of booleans.