%% =(?X, ?Y)
%
-% Unify two variables. This is the most basic operation of Prolog.
+% True if X and Y can be unified. This is the most basic operation of Prolog.
% Unification also happens when doing head matching in a rule.
X = X.
%% true.
%
-% Always succeeds
+% Always true.
true.
%% false.
%
-% Always fails
+% Always false.
false :- '$fail'.
%% current_prolog_flag(Flag, Value)
%
-% Returns the current Value of several flags in the running system. A flag is a setting which value affects
-% internal operation of the Prolog system. Some flags are read-only, while others can be set with set\_prolog\_flag/2.
+% True iff Flag is a flag supported by the processor, and Value is the value currently associated with it.
+% A flag is a setting which value affects internal operation of the Prolog system. Some flags are read-only,
+% while others can be set with set\_prolog\_flag/2.
%
% The flags that Scryer Prolog support are:
% * `max\_arity`: The max arity a predicate can have in Prolog. On Scryer is set to 1023. Read only.
%% set_prolog_flag(Flag, Value).
%
-% Changes the internal value of the flag. To see the list of flags supported by Scryer Prolog,
+% Sets the internal value of the flag. To see the list of flags supported by Scryer Prolog,
% check current\_prolog\_flag/2. The flags that are read only will fail if you try to change their values
set_prolog_flag(Flag, Value) :-
(var(Flag) ; var(Value)),