(defun use-region-p ()
"Return t if the region is active and it is appropriate to act on it.
This is used by commands that act specially on the region under
-Transient Mark mode. It returns t if and only if Transient Mark
-mode is enabled, the mark is active, and the region is non-empty.
-If `use-empty-active-region' is non-nil, it returns t even if the
-region is empty.
+Transient Mark mode.
-For some commands, it may be appropriate to disregard the value
-of `use-empty-active-region'; in that case, use `region-active-p'."
+The return value is t provided Transient Mark mode is enabled and
+the mark is active; and, when `use-empty-active-region' is
+non-nil, provided the region is empty. Otherwise, the return
+value is nil.
+
+For some commands, it may be appropriate to ignore the value of
+`use-empty-active-region'; in that case, use `region-active-p'."
(and (region-active-p)
(or use-empty-active-region (> (region-end) (region-beginning)))))
(defun region-active-p ()
"Return t if Transient Mark mode is enabled and the mark is active.
-Most commands that act on the region if it is active and
-Transient Mark mode is enabled, and on the text near point
-otherwise, should use `use-region-p' instead. That function
-checks the value of `use-empty-active-region' as well."
+Some commands act specially on the region when Transient Mark
+mode is enabled. Usually, such commands should use
+`use-region-p' instead of this function, because `use-region-p'
+also checks the value of `use-empty-active-region'."
(and transient-mark-mode mark-active))
(defvar mark-ring nil