2015-10-12: fix fast-sum test.

fix fast-sum test.

diff --git a/tests/fast-sum.scm b/tests/fast-sum.scm
--- a/tests/fast-sum.scm
+++ b/tests/fast-sum.scm
@@ -1,11 +1,16 @@
 (use-modules (srfi srfi-1))
 
+; only for the nice test
+#!curly-infix
 
 (define-syntax fast-sum
   (syntax-rules (iota)
     ((fast-sum (iota count start))
      (+ 1
-        (apply - (map (lambda (x) (/ (* x (+ x 1)) 2))
-                      (list (+ count (- start 1)) start)))))
+        (apply - 
+          (map (lambda (x) (/ {x * {x + 1} } 2))
+                (list {count + {start - 1}} start)))))
     ((fast-sum e)
      (apply + e))))
+
+
diff --git a/tests/fast-sum.w b/tests/fast-sum.w
--- a/tests/fast-sum.w
+++ b/tests/fast-sum.w
@@ -1,5 +1,7 @@
 use-modules : srfi srfi-1
 
+; only for the nice test
+. #!curly-infix
 
 define-syntax fast-sum
   syntax-rules : iota