In the document
"Changes between Scala Version 1.0 and 2.0"
some of the examples don't compile with 2.3.1 and likely didn't compile with 2.0 either.


(Optional) Add abstract on page 6:
Change
class Inner {
to
abstract class Inner {


Missing ")" and incorrect argument order on page 12:
The last line of sum should change from
else m.add(xs.head, sum(m)(xs.tail)
to
else m.add(xs.head, sum(xs.tail)(m))


(Optional) int2ordered no longer implements Ordered correctly on page 13:
Perhaps this did work for 2.0 and the language has changed since. In this case,   it may be best to leave the code and example as-is, optionally with a disclaimer that Ordered has changed since 2.0.

The following alternative code compiles with 2.3.1 but there's little point adding it because:
(a) I suspect it doesn't compile with Scala 1.0 and/or 2.0
(b) Predef.intWrapper already provides an implicit conversion from int to Ordered[int]
implicit def int2ordered(x: int): Ordered[int] = new Ordered[int] {
def compare(y: Int): int = 
  if (x < y) -1
  else if (x > y) 1
  else 0
}


Excess "if" on page 14:
The last line of merge should change from
else if ys.head :: merge(xs, ys.tail)
to
else ys.head :: merge(xs, ys.tail)


Excess "if" on page 15:
The last line of expanded merge implementation (continued from page 14) should change from
else if ys.head :: merge(xs, ys.tail)(c)
to
else ys.head :: merge(xs, ys.tail)(c)