Fix punctuation typo in functional.md

Author: martinschonger

docs/standard-library/functional.md

@@ -20,7 +20,7 @@ Defines C++ Standard Library functions that help construct *function objects*, a
 
 Algorithms require two types of function objects: *unary* and *binary*. Unary function objects require one argument, and binary function objects require two arguments. A function object and function pointers can be passed as a predicate to an algorithm, but function objects are also adaptable and increase the scope, flexibility, and efficiency of the C++ Standard Library. If, for example, a value needed to be bound to a function before being passed to an algorithm, then a function pointer could not be used. Function adaptors convert function pointers into adaptable function objects that can be bound to a value. The header \<functional> also contains member function adaptors that allow member functions to be called as adaptable function objects. Functions are adaptable if they have nested type declarations specifying their argument and return types. Function objects and their adaptors allow the C++ Standard Library to upgrade existing applications and help integrate the library into the C++ programming environment.
 
-The implementation of the function objects in \<functional> includes *transparent operator functors*. which are specializations of standard function objects and take no template parameters, and perform perfect forwarding of the function arguments and perfect return of the result. These template specializations do not require that you specify argument types when you invoke arithmetic, comparison, logical, and bitwise operator functors. You can overload arithmetic, comparison, logical, or bitwise operators for your own types, or for heterogeneous combinations of types, and then use the transparent operator functors as function arguments. For example, if your type *MyType* implements `operator<`, you can call `sort(my_collection.begin(), my_collection.end(), less<>())` instead of explicitly specifying the type `sort(my_collection.begin(), my_collection.end(), less<MyType>())`.
+The implementation of the function objects in \<functional> includes *transparent operator functors*, which are specializations of standard function objects and take no template parameters, and perform perfect forwarding of the function arguments and perfect return of the result. These template specializations do not require that you specify argument types when you invoke arithmetic, comparison, logical, and bitwise operator functors. You can overload arithmetic, comparison, logical, or bitwise operators for your own types, or for heterogeneous combinations of types, and then use the transparent operator functors as function arguments. For example, if your type *MyType* implements `operator<`, you can call `sort(my_collection.begin(), my_collection.end(), less<>())` instead of explicitly specifying the type `sort(my_collection.begin(), my_collection.end(), less<MyType>())`.
 
 The following features are added in C++11, C++14 and C++17: