Types of cmakelist.txt

Hello
I evaluating the following project and I have some questions regarding the cmakelist.txt files that are part t his project.
The structure is the following:

proj:

-CMakeLists.txt
-Subdirectory 1
-CMakeLists.txt
-main1.cpp
-subdirectory 2
-CMakeLists.txt
-main2.cpp

The first one in subdirectory 1 is pretty standard with all the expected commands like:
cmake_minimum_required(VERSION 3.2…

On the other hand, the second one is totally not standard, at least for me.
It does not start with the cmake_minimum_required command.
Its content is like:

 app_add_module(



	MODULE examples__app_simple_app
        MAIN app_simple_app
	SRCS
		app_simple_app.c
	DEPENDS
	)

where app_add_module is a function that builds a static library.
My question regards the content of second cmakelist.txt.

Is it possible allowed to write a cmakelist.txt without following the standard structure?
Any help will be highly appreciated.

Thanks

The CMakeLists.txt in the subdirectory inherits cmake_minimum_required() and project() from the top-level CMakeLists.txt file, through add_subdirectory(). The top-level CMakeLists.txt always has to have these commands, but they are optional in subdirectories.

Wow
That’s was fast Kyle.
Clear like water.
Thank you very much