логический тип и значения  (boolean type and values)
  
Пролог (Prolog)
This manual page is part of the POSIX Programmer's Manual.  The
       Linux implementation of this interface may differ (consult the
       corresponding Linux manual page for details of Linux behavior),
       or the interface may not be implemented on Linux.
Имя (Name)
stdbool.h — boolean type and values
Синопсис (Synopsis)
#include <stdbool.h>
Описание (Description)
The functionality described on this reference page is aligned
       with the ISO C standard. Any conflict between the requirements
       described here and the ISO C standard is unintentional. This
       volume of POSIX.1‐2017 defers to the ISO C standard.
       The <stdbool.h> header shall define the following macros:
       bool    Expands to _Bool.
       true    Expands to the integer constant 1.
       false   Expands to the integer constant 0.
       __bool_true_false_are_defined
               Expands to the integer constant 1.
       An application may undefine and then possibly redefine the macros
       bool, true, and false.
       The following sections are informative.
Использование в приложениях (Application usage)
None.
Обоснование (Rationale)
None.
Будущие направления (Future directions)
The ability to undefine and redefine the macros bool, true, and
       false is an obsolescent feature and may be removed in a future
       version.
Смотри также (See also)
None.