project-euler.002: simplify euler002a

diff --git a/extra/project-euler/002/002.factor b/extra/project-euler/002/002.factor
index fa0964a71662c2da24a3d90856d979d125d03f25..b1dbc7e0d098a7d6f7463c6a0ae56df2dba2fd9a 100644 (file)
--- a/extra/project-euler/002/002.factor
+++ b/extra/project-euler/002/002.factor
@@ -41,8 +41,7 @@ PRIVATE>
 ! -------------------
 
 : fib-upto* ( n -- seq )
-    0 1 [ pick over >= ] [ [ nip ] 2keep + dup ] produce 3nip
-    but-last-slice { 0 1 } prepend ;
+    [ 1 0 ] dip '[ [ + ] 2keep dup _ < ] [ ] produce 3nip ;
 
 : euler002a ( -- answer )
     4,000,000 fib-upto* [ even? ] filter sum ;