[m-rev.] for review 1/2: Prose changes to about page.

[Paul Bone]

Prose changes to about page.

include/about.inc
    These are the changes that I suggested while reviewing Peter's diff
    yesterday.
---
 include/about.inc | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/include/about.inc b/include/about.inc
index 8f666a1..09fb903 100644
--- a/include/about.inc
+++ b/include/about.inc
@@ -30,10 +30,11 @@ The main features of Mercury are:
 	backtracking will not be needed.
 	</p>
 	<p>
-	Mercury handles dynamic data structures not through Prolog's
-	assert/retract but by providing several abstract data types in
-	the standard Mercury library that manage collections of items
-	with different operations and tradeoffs.
+    Mercury handles dynamic data structures not through Prolog's by
+    providing several abstract data types in the standard Mercury library
+    that manage collections of items with different operations and
+    tradeoffs.
+    Programmers can also create their own abstract data types.
 	</p>
 	</li>
 
@@ -42,10 +43,11 @@ The main features of Mercury are:
 	Mercury is a strongly typed language.
 	</h3>
 	<p>
-	Mercury's type system is based on many-sorted logic with parametric polymorphism, very
-	similar to the type systems of modern functional languages such
-	as ML and Haskell. Programmers must declare the types they need
-	using declarations such as
+    Mercury's type system supports discriminated unions with parametric
+    polymorphism, it is both strong and static.
+    The type system is similar to the type systems of modern functional
+    languages such as ML and Haskell.
+    Programmers must declare the types they need using declarations such as
 	</p>
 	<pre>
 	:- type list(T) --->	[] ; [T | list(T)].
@@ -185,5 +187,5 @@ register variables, the ability to take the addresses of labels, and
 the ability to use inline assembler. Using these extensions, it
 generates code that is significantly better than all previous Prolog
 systems known to us. However, the system does not need these
-extensions, and will work in their absence.
+extensions, it will work in their absence.
 </p>
-- 
1.8.1.3