diff -r f9a059c24aea -r 39c755f41ee8 stage4/generate_c/generate_c_il.cc
--- a/stage4/generate_c/generate_c_il.cc	Thu Aug 22 16:53:17 2013 +0100
+++ b/stage4/generate_c/generate_c_il.cc	Thu Aug 22 18:50:43 2013 +0100
@@ -840,6 +840,14 @@
       break;
     }
     
+    /* We do not yet support embedded IL lists, so we abort the compiler if we find one */
+    /* Note that in IL function calls the syntax does not allow embeded IL lists, so this check is not necessary here! */
+    /*
+    {simple_instr_list_c *instruction_list = dynamic_cast<simple_instr_list_c *>(param_value);
+     if (NULL != instruction_list) STAGE4_ERROR(param_value, param_value, "The compiler does not yet support formal invocations in IL that contain embedded IL lists. Aborting!");
+    }
+    */
+    
     if ((param_value == NULL) && (param_direction == function_param_iterator_c::direction_in)) {
       /* No value given for parameter, so we must use the default... */
       /* First check whether default value specified in function declaration...*/
@@ -1061,6 +1069,11 @@
     if ((param_value == NULL) && !fp_iterator.is_en_eno_param_implicit())
       param_value = function_call_param_iterator.next_nf();
 
+    /* We do not yet support embedded IL lists, so we abort the compiler if we find one */
+    {simple_instr_list_c *instruction_list = dynamic_cast<simple_instr_list_c *>(param_value);
+     if (NULL != instruction_list) STAGE4_ERROR(param_value, param_value, "The compiler does not yet support formal invocations in IL that contain embedded IL lists. Aborting!");
+    }
+    
     symbol_c *param_type = fp_iterator.param_type();
     if (param_type == NULL) ERROR;
     
@@ -1229,6 +1242,11 @@
       break;
     }
     
+    /* We do not yet support embedded IL lists, so we abort the compiler if we find one */
+    {simple_instr_list_c *instruction_list = dynamic_cast<simple_instr_list_c *>(param_value);
+     if (NULL != instruction_list) STAGE4_ERROR(param_value, param_value, "The compiler does not yet support formal invocations in IL that contain embedded IL lists. Aborting!");
+    }
+    
     if ((param_value == NULL) && (param_direction == function_param_iterator_c::direction_in)) {
       /* No value given for parameter, so we must use the default... */
       /* First check whether default value specified in function declaration...*/