[ast2C] Applications to values

src/test2.node

@@ -0,0 +1,10 @@
+node aux (i: int) returns (a, b: int);
+let
+  a = 1 -> pre i;
+  b = 2 * i -> (3 * pre i);
+tel
+
+node n (i: int) returns (o1, o2: int);
+let
+  (o1, o2) = aux (i);
+tel