fix: correct a test file

test file appli_para is now correct and can be launched

test/should_work/appli_para.lus

@@ -23,17 +23,17 @@ IMPORTANT: Ici on compile en --no-prefix pour avoir du code + lisible
 
 node D(x: int) returns (o: int); 
 let
-	o = 0 -> (x - pre x) / 2;
+	o = x / 2;
 tel
 
 node A(x: int) returns (o: int);
 let
-	o = x + (0 -> pre o);
+	o = x * x;
 tel
 
 node C(x, y: int) returns (o: int);
 let
-	o = 0 -> pre (x + y);
+	o = x + y;
 tel