diff --git a/runtime.h b/runtime.h
index 2d6d1a2c..7bd1edd7 100644
--- a/runtime.h
+++ b/runtime.h
@@ -1101,6 +1101,10 @@ static object apply(object cont, object func, object args){
   object result;
   common_type buf;
 
+// TODO: should probably check arg counts and error out if needed
+// TODO: move primitive application to another function
+// TODO: use *primitives* to make a list of all missing prims below
+
   switch(type_of(func)) {
     case primitive_tag:
       if (func == primitive_cons) {
@@ -1135,33 +1139,6 @@ static object apply(object cont, object func, object args){
           result = Cyc_global_variables;
       } else if (func == primitive_has_91cycle_127) {
           result = Cyc_has_cycle(car(args));
-// caar(x) (car(car(x)))
-// cdar(x) (cdr(car(x)))
-// cddr(x) (cdr(cdr(x)))
-// caaar(x) (car(car(car(x))))
-// caadr(x) (car(car(cdr(x))))
-// cadar(x) (car(cdr(car(x))))
-// caddr(x) (car(cdr(cdr(x))))
-// cdaar(x) (cdr(car(car(x))))
-// cdadr(x) (cdr(car(cdr(x))))
-// cddar(x) (cdr(cdr(car(x))))
-// cdddr(x) (cdr(cdr(cdr(x))))
-// caaaar(x) (car(car(car(car(x)))))
-// caaadr(x) (car(car(car(cdr(x)))))
-// caadar(x) (car(car(cdr(car(x)))))
-// caaddr(x) (car(car(cdr(cdr(x)))))
-// cadaar(x) (car(cdr(car(car(x)))))
-// cadadr(x) (car(cdr(car(cdr(x)))))
-// caddar(x) (car(cdr(cdr(car(x)))))
-// cadddr(x) (car(cdr(cdr(cdr(x)))))
-// cdaaar(x) (cdr(car(car(car(x)))))
-// cdaadr(x) (cdr(car(car(cdr(x)))))
-// cdadar(x) (cdr(car(cdr(car(x)))))
-// cdaddr(x) (cdr(car(cdr(cdr(x)))))
-// cddaar(x) (cdr(cdr(car(car(x)))))
-// cddadr(x) (cdr(cdr(car(cdr(x)))))
-// cdddar(x) (cdr(cdr(cdr(car(x)))))
-// cddddr(x) (cdr(cdr(cdr(cdr(x)))))
       } else {
           printf("Unrecognized primitive function: %s\n", ((symbol_type *)func)->pname);
           exit(1);