Make the existence of high(type) clearer, especially near subranges (#18286)

* Make the existence of high(type) clearer, especially around subranges

* Use a better example and dry up the wording

1 files changed, 7 insertions, 4 deletions

diff --git a/doc/manual.rst b/doc/manual.rst
index 867db245b..46a40a690 100644
--- a/doc/manual.rst
+++ b/doc/manual.rst
@@ -989,10 +989,12 @@ Ordinal types have the following characteristics:
 - Ordinal types are countable and ordered. This property allows the operation
   of functions such as `inc`, `ord`, and `dec` on ordinal types to
   be defined.
-- Ordinal values have the smallest possible value. Trying to count further
-  down than the smallest value produces a panic or a static error.
-- Ordinal values have the largest possible value. Trying to count further
-  than the largest value produces a panic or a static error.
+- Ordinal types have a smallest possible value, accessible with `low(type)`.
+  Trying to count further down than the smallest value produces a panic or
+  a static error.
+- Ordinal types have a largest possible value, accessible with `high(type)`.
+  Trying to count further up than the largest value produces a panic or
+  a static error.
 
 Integers, bool, characters, and enumeration types (and subranges of these
 types) belong to ordinal types.
@@ -1095,6 +1097,7 @@ lowest and highest value of the type. For example:
   type
     Subrange = range[0..5]
     PositiveFloat = range[0.0..Inf]
+    Positive* = range[1..high(int)] # as defined in `system`
 
 
 `Subrange` is a subrange of an integer which can only hold the values 0