2016-01-27: fix missing word

fix missing word

diff --git a/docs/fosdem2016.org b/docs/fosdem2016.org
--- a/docs/fosdem2016.org
+++ b/docs/fosdem2016.org
@@ -325,7 +325,7 @@ define : main args
    :BEAMER_env: block
    :END:
 
-- Wisp is implemented in Wisp (850 lines, implementations).
+- Wisp is implemented in Wisp (850 lines, two implementations).
 - Examples: 4 lines (factorial) to 330 lines (advection on icosaheder).
 
 * Try Wisp