diff --git a/tests/loop-rules/ast-rule4.heyvl b/tests/loop-rules/ast-rule4.heyvl
index c96d97ce..33e90366 100644
--- a/tests/loop-rules/ast-rule4.heyvl
+++ b/tests/loop-rules/ast-rule4.heyvl
@@ -1,75 +1,23 @@
 // RUN: @caesar @file
-// Auto-generated by pgcl2heyvl from esc_spline_ast.pgcl
-//
-// HeyVL file to show that C is almost-surely terminating
-// using AST rule by McIver et al. (2018) with
-// invariant = true, variant = x, probability function = 1 / (v + 1), decrease function = 1
-// for the pGCL program C:
-//
-//     nat x;
-//     while (0 < x) {
-//         {
-//             x := 0;
-//         } [1 / (x + 1)] {
-//             x := x + 1;
-//         }
-//     }
 
-// [I] <= \Phi_{[I]}([I])
-proc I_wp_subinvariant(init_x: UInt) -> (x: UInt)
-    pre [true]
-    post [true]
+proc ast_example4() -> ()
+    pre 1
+    post 1
 {
-    var prob_choice: Bool
-    x = init_x
-    if 0 < x {
-        prob_choice = flip(1 / (x + 1))
+    var x: UInt
+    @ast(
+        /* invariant: */    true, 
+        /* variant: */      x, 
+        /* variable: */     v, 
+        /* prob(v): */      1/(v+1), 
+        /* decrease(v): */  1
+    )
+    while x != 0 {
+        var prob_choice: Bool = flip(1 / (x + 1))
         if prob_choice {
             x = 0
         } else {
             x = x + 1
         }
-        assert [true]
-        assume 0
-    } else {}
-}
-
-// !G iff V = 0
-proc termination_condition(x: UInt) -> ()
-{
-    assert ?(!(0 < x) == (x == 0))
-}
-
-// \Phi_{V}(V) <= V
-coproc V_wp_superinvariant(init_x: UInt) -> (x: UInt)
-    pre init_x
-    post x
-{
-    var prob_choice: Bool
-    x = init_x
-    if 0 < x {
-        prob_choice = flip(1 / (x + 1))
-        if prob_choice {
-            x = 0
-        } else {
-            x = x + 1
-        }
-        assert x
-        assume 0
-    } else {}
-}
-
-// [I] * [G] * (p o V) <= \s. wp[P]([V < V(s) - d(V(s))])(s)
-proc progress_condition(init_x: UInt) -> (x: UInt)
-    pre [true] * ([0 < init_x] * (1 / (init_x + 1)))
-    post [x <= (init_x - 1)]
-{
-    var prob_choice: Bool
-    x = init_x
-    prob_choice = flip(1 / (x + 1))
-    if prob_choice {
-        x = 0
-    } else {
-        x = x + 1
     }
-}
+}
\ No newline at end of file