diff --git a/slides/cours_20.md b/slides/cours_20.md
index 511ced6860b3167aaf43cee5af2a4b7687cb8e44..b1db79831742efb57db1319ce7c9c47b782ff41c 100644
--- a/slides/cours_20.md
+++ b/slides/cours_20.md
@@ -852,6 +852,8 @@ bool last_value(node *qt, int *val) {
## Que devient l'arbre avec $\theta=0.5$?
+
+
. . .
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