diff --git a/changelog b/changelog
index ff04512..30cf744 100644
--- a/changelog
+++ b/changelog
@@ -1,3 +1,4 @@
+20080816 tpd src/input/tutchap2.input remove f 0, it takes too long
 20080815 tpd books/bookvol7.1 fix typo, lost $ recovered
 20080815 tpd Makefile make hyperdoc before testing
 20080814 tpd books/bookvol7 handle uncompressed images
diff --git a/src/input/tutchap2.input.pamphlet b/src/input/tutchap2.input.pamphlet
index ae81f5f..2fcb523 100644
--- a/src/input/tutchap2.input.pamphlet
+++ b/src/input/tutchap2.input.pamphlet
@@ -92,7 +92,7 @@ f 1000
 f(n : PositiveInteger) : Any ==                   _
           (local length; length := #((2^n)::String);      _
            if length > 120 then "Too long!" else length)
-f 0
+-- this takes too long to compute -- f 0
 g1(x) == 2*x
 g2(x) == %
 G := 2*x