(Integer Representations): Simplify; delete xref to containing chapter.

c.texi

@@ -12181,18 +12181,19 @@ bits has a range from @math{-2@sup{(@var{n} - 1)}} to @minus{}1 to 0
 to 1 to @math{+2@sup{(@var{n} - 1)} - 1}, inclusive.  The leftmost, or
 high-order, bit is called the @dfn{sign bit}.
 
-@c ??? Needs correcting
+In two's-complement representation, there is only one value that means
+zero, and the most negative number lacks a positive counterpart.  As a
+result, negating that number causes overflow; in practice, its result
+is that number back again.  We will revisit that peculiarity shortly.
 
-There is only one value that means zero, and the most negative number
-lacks a positive counterpart.  As a result, negating that number
-causes overflow; in practice, its result is that number back again.
 For example, a two's-complement signed 8-bit integer can represent all
-decimal numbers from @minus{}128 to +127.  We will revisit that
+decimal numbers from @minus{}128 to +127.  Negating @minus{}128 ought
-peculiarity shortly.
+to give +128, but that value won't fit in 8 bits, so the operation
+yields @minus{}128.
 
-Decades ago, there were computers that didn't use two's-complement
+Decades ago, there were computers that used other representations for
-representation for integers (@pxref{Integers in Depth}), but they are
+signed integers, but they are long gone and not worth any effort to
-long gone and not worth any effort to support.
+support.  The GNU C language does not support them.
 
 @c ??? Is this duplicate?