diff --git a/Ingegneria del Software/0621_6/wrong2.txt b/Ingegneria del Software/0621_6/wrong2.txt
new file mode 100644
index 0000000..81653ea
--- /dev/null
+++ b/Ingegneria del Software/0621_6/wrong2.txt	
@@ -0,0 +1,16 @@
+function next
+input Integer x;
+output Integer y;
+algorithm
+   y := 1 - x;
+end next;
+
+class System
+Integer x;
+initial equation
+x = 0;
+equation
+when sample(0, 1) then
+    x = next(pre(x));
+end when;
+end System;
\ No newline at end of file