Merge pull request #31 from AeneasVerif/son_lean_backend

Improve the Lean backend

7 files changed, 156 insertions, 151 deletions

diff --git a/tests/fstar/misc/Constants.fst b/tests/fstar/misc/Constants.fst
index bf2f0b1b..aae997fa 100644
--- a/tests/fstar/misc/Constants.fst
+++ b/tests/fstar/misc/Constants.fst
@@ -21,7 +21,7 @@ let x1_c : u32 = eval_global x1_body
 let x2_body : result u32 = Return 3
 let x2_c : u32 = eval_global x2_body
 
-(** [constants::incr] *)
+(** [constants::incr]: forward function *)
 let incr_fwd (n : u32) : result u32 =
   u32_add n 1
 
@@ -29,14 +29,14 @@ let incr_fwd (n : u32) : result u32 =
 let x3_body : result u32 = incr_fwd 32
 let x3_c : u32 = eval_global x3_body
 
-(** [constants::mk_pair0] *)
+(** [constants::mk_pair0]: forward function *)
 let mk_pair0_fwd (x : u32) (y : u32) : result (u32 & u32) =
   Return (x, y)
 
 (** [constants::Pair] *)
 type pair_t (t1 t2 : Type0) = { pair_x : t1; pair_y : t2; }
 
-(** [constants::mk_pair1] *)
+(** [constants::mk_pair1]: forward function *)
 let mk_pair1_fwd (x : u32) (y : u32) : result (pair_t u32 u32) =
   Return { pair_x = x; pair_y = y }
 
@@ -59,7 +59,7 @@ let p3_c : pair_t u32 u32 = eval_global p3_body
 (** [constants::Wrap] *)
 type wrap_t (t : Type0) = { wrap_val : t; }
 
-(** [constants::Wrap::{0}::new] *)
+(** [constants::Wrap::{0}::new]: forward function *)
 let wrap_new_fwd (t : Type0) (val0 : t) : result (wrap_t t) =
   Return { wrap_val = val0 }
 
@@ -67,7 +67,7 @@ let wrap_new_fwd (t : Type0) (val0 : t) : result (wrap_t t) =
 let y_body : result (wrap_t i32) = wrap_new_fwd i32 2
 let y_c : wrap_t i32 = eval_global y_body
 
-(** [constants::unwrap_y] *)
+(** [constants::unwrap_y]: forward function *)
 let unwrap_y_fwd : result i32 =
   Return y_c.wrap_val
 
@@ -79,11 +79,11 @@ let yval_c : i32 = eval_global yval_body
 let get_z1_z1_body : result i32 = Return 3
 let get_z1_z1_c : i32 = eval_global get_z1_z1_body
 
-(** [constants::get_z1] *)
+(** [constants::get_z1]: forward function *)
 let get_z1_fwd : result i32 =
   Return get_z1_z1_c
 
-(** [constants::add] *)
+(** [constants::add]: forward function *)
 let add_fwd (a : i32) (b : i32) : result i32 =
   i32_add a b
 
@@ -99,7 +99,7 @@ let q2_c : i32 = eval_global q2_body
 let q3_body : result i32 = add_fwd q2_c 3
 let q3_c : i32 = eval_global q3_body
 
-(** [constants::get_z2] *)
+(** [constants::get_z2]: forward function *)
 let get_z2_fwd : result i32 =
   let* i = get_z1_fwd in let* i0 = add_fwd i q3_c in add_fwd q1_c i0
 
diff --git a/tests/fstar/misc/External.Funs.fst b/tests/fstar/misc/External.Funs.fst
index f70a9fc6..f118a2cf 100644
--- a/tests/fstar/misc/External.Funs.fst
+++ b/tests/fstar/misc/External.Funs.fst
@@ -7,14 +7,14 @@ include External.Opaque
 
 #set-options "--z3rlimit 50 --fuel 1 --ifuel 1"
 
-(** [external::swap] *)
+(** [external::swap]: forward function *)
 let swap_fwd (t : Type0) (x : t) (y : t) (st : state) : result (state & unit) =
   let* (st0, _) = core_mem_swap_fwd t x y st in
   let* (st1, _) = core_mem_swap_back0 t x y st st0 in
   let* (st2, _) = core_mem_swap_back1 t x y st st1 in
   Return (st2, ())
 
-(** [external::swap] *)
+(** [external::swap]: backward function 0 *)
 let swap_back
   (t : Type0) (x : t) (y : t) (st : state) (st0 : state) :
   result (state & (t & t))
@@ -24,20 +24,20 @@ let swap_back
   let* (_, y0) = core_mem_swap_back1 t x y st st2 in
   Return (st0, (x0, y0))
 
-(** [external::test_new_non_zero_u32] *)
+(** [external::test_new_non_zero_u32]: forward function *)
 let test_new_non_zero_u32_fwd
   (x : u32) (st : state) : result (state & core_num_nonzero_non_zero_u32_t) =
   let* (st0, opt) = core_num_nonzero_non_zero_u32_new_fwd x st in
   core_option_option_unwrap_fwd core_num_nonzero_non_zero_u32_t opt st0
 
-(** [external::test_vec] *)
+(** [external::test_vec]: forward function *)
 let test_vec_fwd : result unit =
   let v = vec_new u32 in let* _ = vec_push_back u32 v 0 in Return ()
 
 (** Unit test for [external::test_vec] *)
 let _ = assert_norm (test_vec_fwd = Return ())
 
-(** [external::custom_swap] *)
+(** [external::custom_swap]: forward function *)
 let custom_swap_fwd
   (t : Type0) (x : t) (y : t) (st : state) : result (state & t) =
   let* (st0, _) = core_mem_swap_fwd t x y st in
@@ -45,7 +45,7 @@ let custom_swap_fwd
   let* (st2, _) = core_mem_swap_back1 t x y st st1 in
   Return (st2, x0)
 
-(** [external::custom_swap] *)
+(** [external::custom_swap]: backward function 0 *)
 let custom_swap_back
   (t : Type0) (x : t) (y : t) (st : state) (ret : t) (st0 : state) :
   result (state & (t & t))
@@ -55,19 +55,19 @@ let custom_swap_back
   let* (_, y0) = core_mem_swap_back1 t x y st st2 in
   Return (st0, (ret, y0))
 
-(** [external::test_custom_swap] *)
+(** [external::test_custom_swap]: forward function *)
 let test_custom_swap_fwd
   (x : u32) (y : u32) (st : state) : result (state & unit) =
   let* (st0, _) = custom_swap_fwd u32 x y st in Return (st0, ())
 
-(** [external::test_custom_swap] *)
+(** [external::test_custom_swap]: backward function 0 *)
 let test_custom_swap_back
   (x : u32) (y : u32) (st : state) (st0 : state) :
   result (state & (u32 & u32))
   =
   custom_swap_back u32 x y st 1 st0
 
-(** [external::test_swap_non_zero] *)
+(** [external::test_swap_non_zero]: forward function *)
 let test_swap_non_zero_fwd (x : u32) (st : state) : result (state & u32) =
   let* (st0, _) = swap_fwd u32 x 0 st in
   let* (st1, (x0, _)) = swap_back u32 x 0 st st0 in
diff --git a/tests/fstar/misc/External.Opaque.fsti b/tests/fstar/misc/External.Opaque.fsti
index 7d86405a..2e19f767 100644
--- a/tests/fstar/misc/External.Opaque.fsti
+++ b/tests/fstar/misc/External.Opaque.fsti
@@ -1,27 +1,27 @@
 (** THIS FILE WAS AUTOMATICALLY GENERATED BY AENEAS *)
-(** [external]: opaque function definitions *)
+(** [external]: external function declarations *)
 module External.Opaque
 open Primitives
 include External.Types
 
 #set-options "--z3rlimit 50 --fuel 1 --ifuel 1"
 
-(** [core::mem::swap] *)
+(** [core::mem::swap]: forward function *)
 val core_mem_swap_fwd (t : Type0) : t -> t -> state -> result (state & unit)
 
-(** [core::mem::swap] *)
+(** [core::mem::swap]: backward function 0 *)
 val core_mem_swap_back0
   (t : Type0) : t -> t -> state -> state -> result (state & t)
 
-(** [core::mem::swap] *)
+(** [core::mem::swap]: backward function 1 *)
 val core_mem_swap_back1
   (t : Type0) : t -> t -> state -> state -> result (state & t)
 
-(** [core::num::nonzero::NonZeroU32::{14}::new] *)
+(** [core::num::nonzero::NonZeroU32::{14}::new]: forward function *)
 val core_num_nonzero_non_zero_u32_new_fwd
   : u32 -> state -> result (state & (option core_num_nonzero_non_zero_u32_t))
 
-(** [core::option::Option::{0}::unwrap] *)
+(** [core::option::Option::{0}::unwrap]: forward function *)
 val core_option_option_unwrap_fwd
   (t : Type0) : option t -> state -> result (state & t)
 
diff --git a/tests/fstar/misc/Loops.Funs.fst b/tests/fstar/misc/Loops.Funs.fst
index 7fe175e5..9a80f415 100644
--- a/tests/fstar/misc/Loops.Funs.fst
+++ b/tests/fstar/misc/Loops.Funs.fst
@@ -7,7 +7,7 @@ include Loops.Clauses
 
 #set-options "--z3rlimit 50 --fuel 1 --ifuel 1"
 
-(** [loops::sum] *)
+(** [loops::sum]: loop 0: forward function *)
 let rec sum_loop_fwd
   (max : u32) (i : u32) (s : u32) :
   Tot (result u32) (decreases (sum_loop_decreases max i s))
@@ -16,11 +16,11 @@ let rec sum_loop_fwd
   then let* s0 = u32_add s i in let* i0 = u32_add i 1 in sum_loop_fwd max i0 s0
   else u32_mul s 2
 
-(** [loops::sum] *)
+(** [loops::sum]: forward function *)
 let sum_fwd (max : u32) : result u32 =
   sum_loop_fwd max 0 0
 
-(** [loops::sum_with_mut_borrows] *)
+(** [loops::sum_with_mut_borrows]: loop 0: forward function *)
 let rec sum_with_mut_borrows_loop_fwd
   (max : u32) (mi : u32) (ms : u32) :
   Tot (result u32) (decreases (sum_with_mut_borrows_loop_decreases max mi ms))
@@ -32,11 +32,11 @@ let rec sum_with_mut_borrows_loop_fwd
     sum_with_mut_borrows_loop_fwd max mi0 ms0
   else u32_mul ms 2
 
-(** [loops::sum_with_mut_borrows] *)
+(** [loops::sum_with_mut_borrows]: forward function *)
 let sum_with_mut_borrows_fwd (max : u32) : result u32 =
   sum_with_mut_borrows_loop_fwd max 0 0
 
-(** [loops::sum_with_shared_borrows] *)
+(** [loops::sum_with_shared_borrows]: loop 0: forward function *)
 let rec sum_with_shared_borrows_loop_fwd
   (max : u32) (i : u32) (s : u32) :
   Tot (result u32) (decreases (sum_with_shared_borrows_loop_decreases max i s))
@@ -48,11 +48,12 @@ let rec sum_with_shared_borrows_loop_fwd
     sum_with_shared_borrows_loop_fwd max i0 s0
   else u32_mul s 2
 
-(** [loops::sum_with_shared_borrows] *)
+(** [loops::sum_with_shared_borrows]: forward function *)
 let sum_with_shared_borrows_fwd (max : u32) : result u32 =
   sum_with_shared_borrows_loop_fwd max 0 0
 
-(** [loops::clear] *)
+(** [loops::clear]: loop 0: merged forward/backward function
+    (there is a single backward function, and the forward function returns ()) *)
 let rec clear_loop_fwd_back
   (v : vec u32) (i : usize) :
   Tot (result (vec u32)) (decreases (clear_loop_decreases v i))
@@ -65,11 +66,12 @@ let rec clear_loop_fwd_back
     clear_loop_fwd_back v0 i1
   else Return v
 
-(** [loops::clear] *)
+(** [loops::clear]: merged forward/backward function
+    (there is a single backward function, and the forward function returns ()) *)
 let clear_fwd_back (v : vec u32) : result (vec u32) =
   clear_loop_fwd_back v 0
 
-(** [loops::list_mem] *)
+(** [loops::list_mem]: loop 0: forward function *)
 let rec list_mem_loop_fwd
   (x : u32) (ls : list_t u32) :
   Tot (result bool) (decreases (list_mem_loop_decreases x ls))
@@ -79,11 +81,11 @@ let rec list_mem_loop_fwd
   | ListNil -> Return false
   end
 
-(** [loops::list_mem] *)
+(** [loops::list_mem]: forward function *)
 let list_mem_fwd (x : u32) (ls : list_t u32) : result bool =
   list_mem_loop_fwd x ls
 
-(** [loops::list_nth_mut_loop] *)
+(** [loops::list_nth_mut_loop]: loop 0: forward function *)
 let rec list_nth_mut_loop_loop_fwd
   (t : Type0) (ls : list_t t) (i : u32) :
   Tot (result t) (decreases (list_nth_mut_loop_loop_decreases t ls i))
@@ -96,11 +98,11 @@ let rec list_nth_mut_loop_loop_fwd
   | ListNil -> Fail Failure
   end
 
-(** [loops::list_nth_mut_loop] *)
+(** [loops::list_nth_mut_loop]: forward function *)
 let list_nth_mut_loop_fwd (t : Type0) (ls : list_t t) (i : u32) : result t =
   list_nth_mut_loop_loop_fwd t ls i
 
-(** [loops::list_nth_mut_loop] *)
+(** [loops::list_nth_mut_loop]: loop 0: backward function 0 *)
 let rec list_nth_mut_loop_loop_back
   (t : Type0) (ls : list_t t) (i : u32) (ret : t) :
   Tot (result (list_t t)) (decreases (list_nth_mut_loop_loop_decreases t ls i))
@@ -116,12 +118,12 @@ let rec list_nth_mut_loop_loop_back
   | ListNil -> Fail Failure
   end
 
-(** [loops::list_nth_mut_loop] *)
+(** [loops::list_nth_mut_loop]: backward function 0 *)
 let list_nth_mut_loop_back
   (t : Type0) (ls : list_t t) (i : u32) (ret : t) : result (list_t t) =
   list_nth_mut_loop_loop_back t ls i ret
 
-(** [loops::list_nth_shared_loop] *)
+(** [loops::list_nth_shared_loop]: loop 0: forward function *)
 let rec list_nth_shared_loop_loop_fwd
   (t : Type0) (ls : list_t t) (i : u32) :
   Tot (result t) (decreases (list_nth_shared_loop_loop_decreases t ls i))
@@ -134,11 +136,11 @@ let rec list_nth_shared_loop_loop_fwd
   | ListNil -> Fail Failure
   end
 
-(** [loops::list_nth_shared_loop] *)
+(** [loops::list_nth_shared_loop]: forward function *)
 let list_nth_shared_loop_fwd (t : Type0) (ls : list_t t) (i : u32) : result t =
   list_nth_shared_loop_loop_fwd t ls i
 
-(** [loops::get_elem_mut] *)
+(** [loops::get_elem_mut]: loop 0: forward function *)
 let rec get_elem_mut_loop_fwd
   (x : usize) (ls : list_t usize) :
   Tot (result usize) (decreases (get_elem_mut_loop_decreases x ls))
@@ -148,12 +150,12 @@ let rec get_elem_mut_loop_fwd
   | ListNil -> Fail Failure
   end
 
-(** [loops::get_elem_mut] *)
+(** [loops::get_elem_mut]: forward function *)
 let get_elem_mut_fwd (slots : vec (list_t usize)) (x : usize) : result usize =
   let* l = vec_index_mut_fwd (list_t usize) slots 0 in
   get_elem_mut_loop_fwd x l
 
-(** [loops::get_elem_mut] *)
+(** [loops::get_elem_mut]: loop 0: backward function 0 *)
 let rec get_elem_mut_loop_back
   (x : usize) (ls : list_t usize) (ret : usize) :
   Tot (result (list_t usize)) (decreases (get_elem_mut_loop_decreases x ls))
@@ -166,7 +168,7 @@ let rec get_elem_mut_loop_back
   | ListNil -> Fail Failure
   end
 
-(** [loops::get_elem_mut] *)
+(** [loops::get_elem_mut]: backward function 0 *)
 let get_elem_mut_back
   (slots : vec (list_t usize)) (x : usize) (ret : usize) :
   result (vec (list_t usize))
@@ -175,7 +177,7 @@ let get_elem_mut_back
   let* l0 = get_elem_mut_loop_back x l ret in
   vec_index_mut_back (list_t usize) slots 0 l0
 
-(** [loops::get_elem_shared] *)
+(** [loops::get_elem_shared]: loop 0: forward function *)
 let rec get_elem_shared_loop_fwd
   (x : usize) (ls : list_t usize) :
   Tot (result usize) (decreases (get_elem_shared_loop_decreases x ls))
@@ -185,25 +187,25 @@ let rec get_elem_shared_loop_fwd
   | ListNil -> Fail Failure
   end
 
-(** [loops::get_elem_shared] *)
+(** [loops::get_elem_shared]: forward function *)
 let get_elem_shared_fwd
   (slots : vec (list_t usize)) (x : usize) : result usize =
   let* l = vec_index_fwd (list_t usize) slots 0 in get_elem_shared_loop_fwd x l
 
-(** [loops::id_mut] *)
+(** [loops::id_mut]: forward function *)
 let id_mut_fwd (t : Type0) (ls : list_t t) : result (list_t t) =
   Return ls
 
-(** [loops::id_mut] *)
+(** [loops::id_mut]: backward function 0 *)
 let id_mut_back
   (t : Type0) (ls : list_t t) (ret : list_t t) : result (list_t t) =
   Return ret
 
-(** [loops::id_shared] *)
+(** [loops::id_shared]: forward function *)
 let id_shared_fwd (t : Type0) (ls : list_t t) : result (list_t t) =
   Return ls
 
-(** [loops::list_nth_mut_loop_with_id] *)
+(** [loops::list_nth_mut_loop_with_id]: loop 0: forward function *)
 let rec list_nth_mut_loop_with_id_loop_fwd
   (t : Type0) (i : u32) (ls : list_t t) :
   Tot (result t) (decreases (list_nth_mut_loop_with_id_loop_decreases t i ls))
@@ -216,12 +218,12 @@ let rec list_nth_mut_loop_with_id_loop_fwd
   | ListNil -> Fail Failure
   end
 
-(** [loops::list_nth_mut_loop_with_id] *)
+(** [loops::list_nth_mut_loop_with_id]: forward function *)
 let list_nth_mut_loop_with_id_fwd
   (t : Type0) (ls : list_t t) (i : u32) : result t =
   let* ls0 = id_mut_fwd t ls in list_nth_mut_loop_with_id_loop_fwd t i ls0
 
-(** [loops::list_nth_mut_loop_with_id] *)
+(** [loops::list_nth_mut_loop_with_id]: loop 0: backward function 0 *)
 let rec list_nth_mut_loop_with_id_loop_back
   (t : Type0) (i : u32) (ls : list_t t) (ret : t) :
   Tot (result (list_t t))
@@ -238,14 +240,14 @@ let rec list_nth_mut_loop_with_id_loop_back
   | ListNil -> Fail Failure
   end
 
-(** [loops::list_nth_mut_loop_with_id] *)
+(** [loops::list_nth_mut_loop_with_id]: backward function 0 *)
 let list_nth_mut_loop_with_id_back
   (t : Type0) (ls : list_t t) (i : u32) (ret : t) : result (list_t t) =
   let* ls0 = id_mut_fwd t ls in
   let* l = list_nth_mut_loop_with_id_loop_back t i ls0 ret in
   id_mut_back t ls l
 
-(** [loops::list_nth_shared_loop_with_id] *)
+(** [loops::list_nth_shared_loop_with_id]: loop 0: forward function *)
 let rec list_nth_shared_loop_with_id_loop_fwd
   (t : Type0) (i : u32) (ls : list_t t) :
   Tot (result t)
@@ -259,13 +261,13 @@ let rec list_nth_shared_loop_with_id_loop_fwd
   | ListNil -> Fail Failure
   end
 
-(** [loops::list_nth_shared_loop_with_id] *)
+(** [loops::list_nth_shared_loop_with_id]: forward function *)
 let list_nth_shared_loop_with_id_fwd
   (t : Type0) (ls : list_t t) (i : u32) : result t =
   let* ls0 = id_shared_fwd t ls in
   list_nth_shared_loop_with_id_loop_fwd t i ls0
 
-(** [loops::list_nth_mut_loop_pair] *)
+(** [loops::list_nth_mut_loop_pair]: loop 0: forward function *)
 let rec list_nth_mut_loop_pair_loop_fwd
   (t : Type0) (ls0 : list_t t) (ls1 : list_t t) (i : u32) :
   Tot (result (t & t))
@@ -284,12 +286,12 @@ let rec list_nth_mut_loop_pair_loop_fwd
   | ListNil -> Fail Failure
   end
 
-(** [loops::list_nth_mut_loop_pair] *)
+(** [loops::list_nth_mut_loop_pair]: forward function *)
 let list_nth_mut_loop_pair_fwd
   (t : Type0) (ls0 : list_t t) (ls1 : list_t t) (i : u32) : result (t & t) =
   list_nth_mut_loop_pair_loop_fwd t ls0 ls1 i
 
-(** [loops::list_nth_mut_loop_pair] *)
+(** [loops::list_nth_mut_loop_pair]: loop 0: backward function 0 *)
 let rec list_nth_mut_loop_pair_loop_back'a
   (t : Type0) (ls0 : list_t t) (ls1 : list_t t) (i : u32) (ret : t) :
   Tot (result (list_t t))
@@ -310,14 +312,14 @@ let rec list_nth_mut_loop_pair_loop_back'a
   | ListNil -> Fail Failure
   end
 
-(** [loops::list_nth_mut_loop_pair] *)
+(** [loops::list_nth_mut_loop_pair]: backward function 0 *)
 let list_nth_mut_loop_pair_back'a
   (t : Type0) (ls0 : list_t t) (ls1 : list_t t) (i : u32) (ret : t) :
   result (list_t t)
   =
   list_nth_mut_loop_pair_loop_back'a t ls0 ls1 i ret
 
-(** [loops::list_nth_mut_loop_pair] *)
+(** [loops::list_nth_mut_loop_pair]: loop 0: backward function 1 *)
 let rec list_nth_mut_loop_pair_loop_back'b
   (t : Type0) (ls0 : list_t t) (ls1 : list_t t) (i : u32) (ret : t) :
   Tot (result (list_t t))
@@ -338,14 +340,14 @@ let rec list_nth_mut_loop_pair_loop_back'b
   | ListNil -> Fail Failure
   end
 
-(** [loops::list_nth_mut_loop_pair] *)
+(** [loops::list_nth_mut_loop_pair]: backward function 1 *)
 let list_nth_mut_loop_pair_back'b
   (t : Type0) (ls0 : list_t t) (ls1 : list_t t) (i : u32) (ret : t) :
   result (list_t t)
   =
   list_nth_mut_loop_pair_loop_back'b t ls0 ls1 i ret
 
-(** [loops::list_nth_shared_loop_pair] *)
+(** [loops::list_nth_shared_loop_pair]: loop 0: forward function *)
 let rec list_nth_shared_loop_pair_loop_fwd
   (t : Type0) (ls0 : list_t t) (ls1 : list_t t) (i : u32) :
   Tot (result (t & t))
@@ -365,12 +367,12 @@ let rec list_nth_shared_loop_pair_loop_fwd
   | ListNil -> Fail Failure
   end
 
-(** [loops::list_nth_shared_loop_pair] *)
+(** [loops::list_nth_shared_loop_pair]: forward function *)
 let list_nth_shared_loop_pair_fwd
   (t : Type0) (ls0 : list_t t) (ls1 : list_t t) (i : u32) : result (t & t) =
   list_nth_shared_loop_pair_loop_fwd t ls0 ls1 i
 
-(** [loops::list_nth_mut_loop_pair_merge] *)
+(** [loops::list_nth_mut_loop_pair_merge]: loop 0: forward function *)
 let rec list_nth_mut_loop_pair_merge_loop_fwd
   (t : Type0) (ls0 : list_t t) (ls1 : list_t t) (i : u32) :
   Tot (result (t & t))
@@ -390,12 +392,12 @@ let rec list_nth_mut_loop_pair_merge_loop_fwd
   | ListNil -> Fail Failure
   end
 
-(** [loops::list_nth_mut_loop_pair_merge] *)
+(** [loops::list_nth_mut_loop_pair_merge]: forward function *)
 let list_nth_mut_loop_pair_merge_fwd
   (t : Type0) (ls0 : list_t t) (ls1 : list_t t) (i : u32) : result (t & t) =
   list_nth_mut_loop_pair_merge_loop_fwd t ls0 ls1 i
 
-(** [loops::list_nth_mut_loop_pair_merge] *)
+(** [loops::list_nth_mut_loop_pair_merge]: loop 0: backward function 0 *)
 let rec list_nth_mut_loop_pair_merge_loop_back
   (t : Type0) (ls0 : list_t t) (ls1 : list_t t) (i : u32) (ret : (t & t)) :
   Tot (result ((list_t t) & (list_t t)))
@@ -417,14 +419,14 @@ let rec list_nth_mut_loop_pair_merge_loop_back
   | ListNil -> Fail Failure
   end
 
-(** [loops::list_nth_mut_loop_pair_merge] *)
+(** [loops::list_nth_mut_loop_pair_merge]: backward function 0 *)
 let list_nth_mut_loop_pair_merge_back
   (t : Type0) (ls0 : list_t t) (ls1 : list_t t) (i : u32) (ret : (t & t)) :
   result ((list_t t) & (list_t t))
   =
   list_nth_mut_loop_pair_merge_loop_back t ls0 ls1 i ret
 
-(** [loops::list_nth_shared_loop_pair_merge] *)
+(** [loops::list_nth_shared_loop_pair_merge]: loop 0: forward function *)
 let rec list_nth_shared_loop_pair_merge_loop_fwd
   (t : Type0) (ls0 : list_t t) (ls1 : list_t t) (i : u32) :
   Tot (result (t & t))
@@ -444,12 +446,12 @@ let rec list_nth_shared_loop_pair_merge_loop_fwd
   | ListNil -> Fail Failure
   end
 
-(** [loops::list_nth_shared_loop_pair_merge] *)
+(** [loops::list_nth_shared_loop_pair_merge]: forward function *)
 let list_nth_shared_loop_pair_merge_fwd
   (t : Type0) (ls0 : list_t t) (ls1 : list_t t) (i : u32) : result (t & t) =
   list_nth_shared_loop_pair_merge_loop_fwd t ls0 ls1 i
 
-(** [loops::list_nth_mut_shared_loop_pair] *)
+(** [loops::list_nth_mut_shared_loop_pair]: loop 0: forward function *)
 let rec list_nth_mut_shared_loop_pair_loop_fwd
   (t : Type0) (ls0 : list_t t) (ls1 : list_t t) (i : u32) :
   Tot (result (t & t))
@@ -469,12 +471,12 @@ let rec list_nth_mut_shared_loop_pair_loop_fwd
   | ListNil -> Fail Failure
   end
 
-(** [loops::list_nth_mut_shared_loop_pair] *)
+(** [loops::list_nth_mut_shared_loop_pair]: forward function *)
 let list_nth_mut_shared_loop_pair_fwd
   (t : Type0) (ls0 : list_t t) (ls1 : list_t t) (i : u32) : result (t & t) =
   list_nth_mut_shared_loop_pair_loop_fwd t ls0 ls1 i
 
-(** [loops::list_nth_mut_shared_loop_pair] *)
+(** [loops::list_nth_mut_shared_loop_pair]: loop 0: backward function 0 *)
 let rec list_nth_mut_shared_loop_pair_loop_back
   (t : Type0) (ls0 : list_t t) (ls1 : list_t t) (i : u32) (ret : t) :
   Tot (result (list_t t))
@@ -495,14 +497,14 @@ let rec list_nth_mut_shared_loop_pair_loop_back
   | ListNil -> Fail Failure
   end
 
-(** [loops::list_nth_mut_shared_loop_pair] *)
+(** [loops::list_nth_mut_shared_loop_pair]: backward function 0 *)
 let list_nth_mut_shared_loop_pair_back
   (t : Type0) (ls0 : list_t t) (ls1 : list_t t) (i : u32) (ret : t) :
   result (list_t t)
   =
   list_nth_mut_shared_loop_pair_loop_back t ls0 ls1 i ret
 
-(** [loops::list_nth_mut_shared_loop_pair_merge] *)
+(** [loops::list_nth_mut_shared_loop_pair_merge]: loop 0: forward function *)
 let rec list_nth_mut_shared_loop_pair_merge_loop_fwd
   (t : Type0) (ls0 : list_t t) (ls1 : list_t t) (i : u32) :
   Tot (result (t & t))
@@ -522,12 +524,12 @@ let rec list_nth_mut_shared_loop_pair_merge_loop_fwd
   | ListNil -> Fail Failure
   end
 
-(** [loops::list_nth_mut_shared_loop_pair_merge] *)
+(** [loops::list_nth_mut_shared_loop_pair_merge]: forward function *)
 let list_nth_mut_shared_loop_pair_merge_fwd
   (t : Type0) (ls0 : list_t t) (ls1 : list_t t) (i : u32) : result (t & t) =
   list_nth_mut_shared_loop_pair_merge_loop_fwd t ls0 ls1 i
 
-(** [loops::list_nth_mut_shared_loop_pair_merge] *)
+(** [loops::list_nth_mut_shared_loop_pair_merge]: loop 0: backward function 0 *)
 let rec list_nth_mut_shared_loop_pair_merge_loop_back
   (t : Type0) (ls0 : list_t t) (ls1 : list_t t) (i : u32) (ret : t) :
   Tot (result (list_t t))
@@ -549,14 +551,14 @@ let rec list_nth_mut_shared_loop_pair_merge_loop_back
   | ListNil -> Fail Failure
   end
 
-(** [loops::list_nth_mut_shared_loop_pair_merge] *)
+(** [loops::list_nth_mut_shared_loop_pair_merge]: backward function 0 *)
 let list_nth_mut_shared_loop_pair_merge_back
   (t : Type0) (ls0 : list_t t) (ls1 : list_t t) (i : u32) (ret : t) :
   result (list_t t)
   =
   list_nth_mut_shared_loop_pair_merge_loop_back t ls0 ls1 i ret
 
-(** [loops::list_nth_shared_mut_loop_pair] *)
+(** [loops::list_nth_shared_mut_loop_pair]: loop 0: forward function *)
 let rec list_nth_shared_mut_loop_pair_loop_fwd
   (t : Type0) (ls0 : list_t t) (ls1 : list_t t) (i : u32) :
   Tot (result (t & t))
@@ -576,12 +578,12 @@ let rec list_nth_shared_mut_loop_pair_loop_fwd
   | ListNil -> Fail Failure
   end
 
-(** [loops::list_nth_shared_mut_loop_pair] *)
+(** [loops::list_nth_shared_mut_loop_pair]: forward function *)
 let list_nth_shared_mut_loop_pair_fwd
   (t : Type0) (ls0 : list_t t) (ls1 : list_t t) (i : u32) : result (t & t) =
   list_nth_shared_mut_loop_pair_loop_fwd t ls0 ls1 i
 
-(** [loops::list_nth_shared_mut_loop_pair] *)
+(** [loops::list_nth_shared_mut_loop_pair]: loop 0: backward function 1 *)
 let rec list_nth_shared_mut_loop_pair_loop_back
   (t : Type0) (ls0 : list_t t) (ls1 : list_t t) (i : u32) (ret : t) :
   Tot (result (list_t t))
@@ -602,14 +604,14 @@ let rec list_nth_shared_mut_loop_pair_loop_back
   | ListNil -> Fail Failure
   end
 
-(** [loops::list_nth_shared_mut_loop_pair] *)
+(** [loops::list_nth_shared_mut_loop_pair]: backward function 1 *)
 let list_nth_shared_mut_loop_pair_back
   (t : Type0) (ls0 : list_t t) (ls1 : list_t t) (i : u32) (ret : t) :
   result (list_t t)
   =
   list_nth_shared_mut_loop_pair_loop_back t ls0 ls1 i ret
 
-(** [loops::list_nth_shared_mut_loop_pair_merge] *)
+(** [loops::list_nth_shared_mut_loop_pair_merge]: loop 0: forward function *)
 let rec list_nth_shared_mut_loop_pair_merge_loop_fwd
   (t : Type0) (ls0 : list_t t) (ls1 : list_t t) (i : u32) :
   Tot (result (t & t))
@@ -629,12 +631,12 @@ let rec list_nth_shared_mut_loop_pair_merge_loop_fwd
   | ListNil -> Fail Failure
   end
 
-(** [loops::list_nth_shared_mut_loop_pair_merge] *)
+(** [loops::list_nth_shared_mut_loop_pair_merge]: forward function *)
 let list_nth_shared_mut_loop_pair_merge_fwd
   (t : Type0) (ls0 : list_t t) (ls1 : list_t t) (i : u32) : result (t & t) =
   list_nth_shared_mut_loop_pair_merge_loop_fwd t ls0 ls1 i
 
-(** [loops::list_nth_shared_mut_loop_pair_merge] *)
+(** [loops::list_nth_shared_mut_loop_pair_merge]: loop 0: backward function 0 *)
 let rec list_nth_shared_mut_loop_pair_merge_loop_back
   (t : Type0) (ls0 : list_t t) (ls1 : list_t t) (i : u32) (ret : t) :
   Tot (result (list_t t))
@@ -656,7 +658,7 @@ let rec list_nth_shared_mut_loop_pair_merge_loop_back
   | ListNil -> Fail Failure
   end
 
-(** [loops::list_nth_shared_mut_loop_pair_merge] *)
+(** [loops::list_nth_shared_mut_loop_pair_merge]: backward function 0 *)
 let list_nth_shared_mut_loop_pair_merge_back
   (t : Type0) (ls0 : list_t t) (ls1 : list_t t) (i : u32) (ret : t) :
   result (list_t t)
diff --git a/tests/fstar/misc/NoNestedBorrows.fst b/tests/fstar/misc/NoNestedBorrows.fst
index 3770ab5d..d790bfa9 100644
--- a/tests/fstar/misc/NoNestedBorrows.fst
+++ b/tests/fstar/misc/NoNestedBorrows.fst
@@ -30,46 +30,46 @@ type sum_t (t1 t2 : Type0) =
 | SumLeft : t1 -> sum_t t1 t2
 | SumRight : t2 -> sum_t t1 t2
 
-(** [no_nested_borrows::neg_test] *)
+(** [no_nested_borrows::neg_test]: forward function *)
 let neg_test_fwd (x : i32) : result i32 =
   i32_neg x
 
-(** [no_nested_borrows::add_test] *)
+(** [no_nested_borrows::add_test]: forward function *)
 let add_test_fwd (x : u32) (y : u32) : result u32 =
   u32_add x y
 
-(** [no_nested_borrows::subs_test] *)
+(** [no_nested_borrows::subs_test]: forward function *)
 let subs_test_fwd (x : u32) (y : u32) : result u32 =
   u32_sub x y
 
-(** [no_nested_borrows::div_test] *)
+(** [no_nested_borrows::div_test]: forward function *)
 let div_test_fwd (x : u32) (y : u32) : result u32 =
   u32_div x y
 
-(** [no_nested_borrows::div_test1] *)
+(** [no_nested_borrows::div_test1]: forward function *)
 let div_test1_fwd (x : u32) : result u32 =
   u32_div x 2
 
-(** [no_nested_borrows::rem_test] *)
+(** [no_nested_borrows::rem_test]: forward function *)
 let rem_test_fwd (x : u32) (y : u32) : result u32 =
   u32_rem x y
 
-(** [no_nested_borrows::cast_test] *)
+(** [no_nested_borrows::cast_test]: forward function *)
 let cast_test_fwd (x : u32) : result i32 =
   scalar_cast U32 I32 x
 
-(** [no_nested_borrows::test2] *)
+(** [no_nested_borrows::test2]: forward function *)
 let test2_fwd : result unit =
   let* _ = u32_add 23 44 in Return ()
 
 (** Unit test for [no_nested_borrows::test2] *)
 let _ = assert_norm (test2_fwd = Return ())
 
-(** [no_nested_borrows::get_max] *)
+(** [no_nested_borrows::get_max]: forward function *)
 let get_max_fwd (x : u32) (y : u32) : result u32 =
   if x >= y then Return x else Return y
 
-(** [no_nested_borrows::test3] *)
+(** [no_nested_borrows::test3]: forward function *)
 let test3_fwd : result unit =
   let* x = get_max_fwd 4 3 in
   let* y = get_max_fwd 10 11 in
@@ -79,21 +79,21 @@ let test3_fwd : result unit =
 (** Unit test for [no_nested_borrows::test3] *)
 let _ = assert_norm (test3_fwd = Return ())
 
-(** [no_nested_borrows::test_neg1] *)
+(** [no_nested_borrows::test_neg1]: forward function *)
 let test_neg1_fwd : result unit =
   let* y = i32_neg 3 in if not (y = -3) then Fail Failure else Return ()
 
 (** Unit test for [no_nested_borrows::test_neg1] *)
 let _ = assert_norm (test_neg1_fwd = Return ())
 
-(** [no_nested_borrows::refs_test1] *)
+(** [no_nested_borrows::refs_test1]: forward function *)
 let refs_test1_fwd : result unit =
   if not (1 = 1) then Fail Failure else Return ()
 
 (** Unit test for [no_nested_borrows::refs_test1] *)
 let _ = assert_norm (refs_test1_fwd = Return ())
 
-(** [no_nested_borrows::refs_test2] *)
+(** [no_nested_borrows::refs_test2]: forward function *)
 let refs_test2_fwd : result unit =
   if not (2 = 2)
   then Fail Failure
@@ -108,47 +108,47 @@ let refs_test2_fwd : result unit =
 (** Unit test for [no_nested_borrows::refs_test2] *)
 let _ = assert_norm (refs_test2_fwd = Return ())
 
-(** [no_nested_borrows::test_list1] *)
+(** [no_nested_borrows::test_list1]: forward function *)
 let test_list1_fwd : result unit =
   Return ()
 
 (** Unit test for [no_nested_borrows::test_list1] *)
 let _ = assert_norm (test_list1_fwd = Return ())
 
-(** [no_nested_borrows::test_box1] *)
+(** [no_nested_borrows::test_box1]: forward function *)
 let test_box1_fwd : result unit =
   let b = 1 in let x = b in if not (x = 1) then Fail Failure else Return ()
 
 (** Unit test for [no_nested_borrows::test_box1] *)
 let _ = assert_norm (test_box1_fwd = Return ())
 
-(** [no_nested_borrows::copy_int] *)
+(** [no_nested_borrows::copy_int]: forward function *)
 let copy_int_fwd (x : i32) : result i32 =
   Return x
 
-(** [no_nested_borrows::test_unreachable] *)
+(** [no_nested_borrows::test_unreachable]: forward function *)
 let test_unreachable_fwd (b : bool) : result unit =
   if b then Fail Failure else Return ()
 
-(** [no_nested_borrows::test_panic] *)
+(** [no_nested_borrows::test_panic]: forward function *)
 let test_panic_fwd (b : bool) : result unit =
   if b then Fail Failure else Return ()
 
-(** [no_nested_borrows::test_copy_int] *)
+(** [no_nested_borrows::test_copy_int]: forward function *)
 let test_copy_int_fwd : result unit =
   let* y = copy_int_fwd 0 in if not (0 = y) then Fail Failure else Return ()
 
 (** Unit test for [no_nested_borrows::test_copy_int] *)
 let _ = assert_norm (test_copy_int_fwd = Return ())
 
-(** [no_nested_borrows::is_cons] *)
+(** [no_nested_borrows::is_cons]: forward function *)
 let is_cons_fwd (t : Type0) (l : list_t t) : result bool =
   begin match l with
   | ListCons x l0 -> Return true
   | ListNil -> Return false
   end
 
-(** [no_nested_borrows::test_is_cons] *)
+(** [no_nested_borrows::test_is_cons]: forward function *)
 let test_is_cons_fwd : result unit =
   let l = ListNil in
   let* b = is_cons_fwd i32 (ListCons 0 l) in
@@ -157,14 +157,14 @@ let test_is_cons_fwd : result unit =
 (** Unit test for [no_nested_borrows::test_is_cons] *)
 let _ = assert_norm (test_is_cons_fwd = Return ())
 
-(** [no_nested_borrows::split_list] *)
+(** [no_nested_borrows::split_list]: forward function *)
 let split_list_fwd (t : Type0) (l : list_t t) : result (t & (list_t t)) =
   begin match l with
   | ListCons hd tl -> Return (hd, tl)
   | ListNil -> Fail Failure
   end
 
-(** [no_nested_borrows::test_split_list] *)
+(** [no_nested_borrows::test_split_list]: forward function *)
 let test_split_list_fwd : result unit =
   let l = ListNil in
   let* p = split_list_fwd i32 (ListCons 0 l) in
@@ -174,16 +174,16 @@ let test_split_list_fwd : result unit =
 (** Unit test for [no_nested_borrows::test_split_list] *)
 let _ = assert_norm (test_split_list_fwd = Return ())
 
-(** [no_nested_borrows::choose] *)
+(** [no_nested_borrows::choose]: forward function *)
 let choose_fwd (t : Type0) (b : bool) (x : t) (y : t) : result t =
   if b then Return x else Return y
 
-(** [no_nested_borrows::choose] *)
+(** [no_nested_borrows::choose]: backward function 0 *)
 let choose_back
   (t : Type0) (b : bool) (x : t) (y : t) (ret : t) : result (t & t) =
   if b then Return (ret, y) else Return (x, ret)
 
-(** [no_nested_borrows::choose_test] *)
+(** [no_nested_borrows::choose_test]: forward function *)
 let choose_test_fwd : result unit =
   let* z = choose_fwd i32 true 0 0 in
   let* z0 = i32_add z 1 in
@@ -198,7 +198,7 @@ let choose_test_fwd : result unit =
 (** Unit test for [no_nested_borrows::choose_test] *)
 let _ = assert_norm (choose_test_fwd = Return ())
 
-(** [no_nested_borrows::test_char] *)
+(** [no_nested_borrows::test_char]: forward function *)
 let test_char_fwd : result char =
   Return 'a'
 
@@ -212,14 +212,14 @@ and tree_t (t : Type0) =
 | TreeLeaf : t -> tree_t t
 | TreeNode : t -> node_elem_t t -> tree_t t -> tree_t t
 
-(** [no_nested_borrows::list_length] *)
+(** [no_nested_borrows::list_length]: forward function *)
 let rec list_length_fwd (t : Type0) (l : list_t t) : result u32 =
   begin match l with
   | ListCons x l1 -> let* i = list_length_fwd t l1 in u32_add 1 i
   | ListNil -> Return 0
   end
 
-(** [no_nested_borrows::list_nth_shared] *)
+(** [no_nested_borrows::list_nth_shared]: forward function *)
 let rec list_nth_shared_fwd (t : Type0) (l : list_t t) (i : u32) : result t =
   begin match l with
   | ListCons x tl ->
@@ -229,7 +229,7 @@ let rec list_nth_shared_fwd (t : Type0) (l : list_t t) (i : u32) : result t =
   | ListNil -> Fail Failure
   end
 
-(** [no_nested_borrows::list_nth_mut] *)
+(** [no_nested_borrows::list_nth_mut]: forward function *)
 let rec list_nth_mut_fwd (t : Type0) (l : list_t t) (i : u32) : result t =
   begin match l with
   | ListCons x tl ->
@@ -239,7 +239,7 @@ let rec list_nth_mut_fwd (t : Type0) (l : list_t t) (i : u32) : result t =
   | ListNil -> Fail Failure
   end
 
-(** [no_nested_borrows::list_nth_mut] *)
+(** [no_nested_borrows::list_nth_mut]: backward function 0 *)
 let rec list_nth_mut_back
   (t : Type0) (l : list_t t) (i : u32) (ret : t) : result (list_t t) =
   begin match l with
@@ -253,7 +253,7 @@ let rec list_nth_mut_back
   | ListNil -> Fail Failure
   end
 
-(** [no_nested_borrows::list_rev_aux] *)
+(** [no_nested_borrows::list_rev_aux]: forward function *)
 let rec list_rev_aux_fwd
   (t : Type0) (li : list_t t) (lo : list_t t) : result (list_t t) =
   begin match li with
@@ -261,12 +261,13 @@ let rec list_rev_aux_fwd
   | ListNil -> Return lo
   end
 
-(** [no_nested_borrows::list_rev] *)
+(** [no_nested_borrows::list_rev]: merged forward/backward function
+    (there is a single backward function, and the forward function returns ()) *)
 let list_rev_fwd_back (t : Type0) (l : list_t t) : result (list_t t) =
   let li = mem_replace_fwd (list_t t) l ListNil in
   list_rev_aux_fwd t li ListNil
 
-(** [no_nested_borrows::test_list_functions] *)
+(** [no_nested_borrows::test_list_functions]: forward function *)
 let test_list_functions_fwd : result unit =
   let l = ListNil in
   let l0 = ListCons 2 l in
@@ -302,48 +303,48 @@ let test_list_functions_fwd : result unit =
 (** Unit test for [no_nested_borrows::test_list_functions] *)
 let _ = assert_norm (test_list_functions_fwd = Return ())
 
-(** [no_nested_borrows::id_mut_pair1] *)
+(** [no_nested_borrows::id_mut_pair1]: forward function *)
 let id_mut_pair1_fwd (t1 t2 : Type0) (x : t1) (y : t2) : result (t1 & t2) =
   Return (x, y)
 
-(** [no_nested_borrows::id_mut_pair1] *)
+(** [no_nested_borrows::id_mut_pair1]: backward function 0 *)
 let id_mut_pair1_back
   (t1 t2 : Type0) (x : t1) (y : t2) (ret : (t1 & t2)) : result (t1 & t2) =
   let (x0, x1) = ret in Return (x0, x1)
 
-(** [no_nested_borrows::id_mut_pair2] *)
+(** [no_nested_borrows::id_mut_pair2]: forward function *)
 let id_mut_pair2_fwd (t1 t2 : Type0) (p : (t1 & t2)) : result (t1 & t2) =
   let (x, x0) = p in Return (x, x0)
 
-(** [no_nested_borrows::id_mut_pair2] *)
+(** [no_nested_borrows::id_mut_pair2]: backward function 0 *)
 let id_mut_pair2_back
   (t1 t2 : Type0) (p : (t1 & t2)) (ret : (t1 & t2)) : result (t1 & t2) =
   let (x, x0) = ret in Return (x, x0)
 
-(** [no_nested_borrows::id_mut_pair3] *)
+(** [no_nested_borrows::id_mut_pair3]: forward function *)
 let id_mut_pair3_fwd (t1 t2 : Type0) (x : t1) (y : t2) : result (t1 & t2) =
   Return (x, y)
 
-(** [no_nested_borrows::id_mut_pair3] *)
+(** [no_nested_borrows::id_mut_pair3]: backward function 0 *)
 let id_mut_pair3_back'a
   (t1 t2 : Type0) (x : t1) (y : t2) (ret : t1) : result t1 =
   Return ret
 
-(** [no_nested_borrows::id_mut_pair3] *)
+(** [no_nested_borrows::id_mut_pair3]: backward function 1 *)
 let id_mut_pair3_back'b
   (t1 t2 : Type0) (x : t1) (y : t2) (ret : t2) : result t2 =
   Return ret
 
-(** [no_nested_borrows::id_mut_pair4] *)
+(** [no_nested_borrows::id_mut_pair4]: forward function *)
 let id_mut_pair4_fwd (t1 t2 : Type0) (p : (t1 & t2)) : result (t1 & t2) =
   let (x, x0) = p in Return (x, x0)
 
-(** [no_nested_borrows::id_mut_pair4] *)
+(** [no_nested_borrows::id_mut_pair4]: backward function 0 *)
 let id_mut_pair4_back'a
   (t1 t2 : Type0) (p : (t1 & t2)) (ret : t1) : result t1 =
   Return ret
 
-(** [no_nested_borrows::id_mut_pair4] *)
+(** [no_nested_borrows::id_mut_pair4]: backward function 1 *)
 let id_mut_pair4_back'b
   (t1 t2 : Type0) (p : (t1 & t2)) (ret : t2) : result t2 =
   Return ret
@@ -351,15 +352,15 @@ let id_mut_pair4_back'b
 (** [no_nested_borrows::StructWithTuple] *)
 type struct_with_tuple_t (t1 t2 : Type0) = { struct_with_tuple_p : (t1 & t2); }
 
-(** [no_nested_borrows::new_tuple1] *)
+(** [no_nested_borrows::new_tuple1]: forward function *)
 let new_tuple1_fwd : result (struct_with_tuple_t u32 u32) =
   Return { struct_with_tuple_p = (1, 2) }
 
-(** [no_nested_borrows::new_tuple2] *)
+(** [no_nested_borrows::new_tuple2]: forward function *)
 let new_tuple2_fwd : result (struct_with_tuple_t i16 i16) =
   Return { struct_with_tuple_p = (1, 2) }
 
-(** [no_nested_borrows::new_tuple3] *)
+(** [no_nested_borrows::new_tuple3]: forward function *)
 let new_tuple3_fwd : result (struct_with_tuple_t u64 i64) =
   Return { struct_with_tuple_p = (1, 2) }
 
@@ -369,11 +370,11 @@ type struct_with_pair_t (t1 t2 : Type0) =
   struct_with_pair_p : pair_t t1 t2;
 }
 
-(** [no_nested_borrows::new_pair1] *)
+(** [no_nested_borrows::new_pair1]: forward function *)
 let new_pair1_fwd : result (struct_with_pair_t u32 u32) =
   Return { struct_with_pair_p = { pair_x = 1; pair_y = 2 } }
 
-(** [no_nested_borrows::test_constants] *)
+(** [no_nested_borrows::test_constants]: forward function *)
 let test_constants_fwd : result unit =
   let* swt = new_tuple1_fwd in
   let (i, _) = swt.struct_with_tuple_p in
@@ -398,31 +399,32 @@ let test_constants_fwd : result unit =
 (** Unit test for [no_nested_borrows::test_constants] *)
 let _ = assert_norm (test_constants_fwd = Return ())
 
-(** [no_nested_borrows::test_weird_borrows1] *)
+(** [no_nested_borrows::test_weird_borrows1]: forward function *)
 let test_weird_borrows1_fwd : result unit =
   Return ()
 
 (** Unit test for [no_nested_borrows::test_weird_borrows1] *)
 let _ = assert_norm (test_weird_borrows1_fwd = Return ())
 
-(** [no_nested_borrows::test_mem_replace] *)
+(** [no_nested_borrows::test_mem_replace]: merged forward/backward function
+    (there is a single backward function, and the forward function returns ()) *)
 let test_mem_replace_fwd_back (px : u32) : result u32 =
   let y = mem_replace_fwd u32 px 1 in
   if not (y = 0) then Fail Failure else Return 2
 
-(** [no_nested_borrows::test_shared_borrow_bool1] *)
+(** [no_nested_borrows::test_shared_borrow_bool1]: forward function *)
 let test_shared_borrow_bool1_fwd (b : bool) : result u32 =
   if b then Return 0 else Return 1
 
-(** [no_nested_borrows::test_shared_borrow_bool2] *)
+(** [no_nested_borrows::test_shared_borrow_bool2]: forward function *)
 let test_shared_borrow_bool2_fwd : result u32 =
   Return 0
 
-(** [no_nested_borrows::test_shared_borrow_enum1] *)
+(** [no_nested_borrows::test_shared_borrow_enum1]: forward function *)
 let test_shared_borrow_enum1_fwd (l : list_t u32) : result u32 =
   begin match l with | ListCons i l0 -> Return 1 | ListNil -> Return 0 end
 
-(** [no_nested_borrows::test_shared_borrow_enum2] *)
+(** [no_nested_borrows::test_shared_borrow_enum2]: forward function *)
 let test_shared_borrow_enum2_fwd : result u32 =
   Return 0
 
diff --git a/tests/fstar/misc/Paper.fst b/tests/fstar/misc/Paper.fst
index 4ab31de3..e2d692c2 100644
--- a/tests/fstar/misc/Paper.fst
+++ b/tests/fstar/misc/Paper.fst
@@ -5,11 +5,12 @@ open Primitives
 
 #set-options "--z3rlimit 50 --fuel 1 --ifuel 1"
 
-(** [paper::ref_incr] *)
+(** [paper::ref_incr]: merged forward/backward function
+    (there is a single backward function, and the forward function returns ()) *)
 let ref_incr_fwd_back (x : i32) : result i32 =
   i32_add x 1
 
-(** [paper::test_incr] *)
+(** [paper::test_incr]: forward function *)
 let test_incr_fwd : result unit =
   let* x = ref_incr_fwd_back 0 in
   if not (x = 1) then Fail Failure else Return ()
@@ -17,16 +18,16 @@ let test_incr_fwd : result unit =
 (** Unit test for [paper::test_incr] *)
 let _ = assert_norm (test_incr_fwd = Return ())
 
-(** [paper::choose] *)
+(** [paper::choose]: forward function *)
 let choose_fwd (t : Type0) (b : bool) (x : t) (y : t) : result t =
   if b then Return x else Return y
 
-(** [paper::choose] *)
+(** [paper::choose]: backward function 0 *)
 let choose_back
   (t : Type0) (b : bool) (x : t) (y : t) (ret : t) : result (t & t) =
   if b then Return (ret, y) else Return (x, ret)
 
-(** [paper::test_choose] *)
+(** [paper::test_choose]: forward function *)
 let test_choose_fwd : result unit =
   let* z = choose_fwd i32 true 0 0 in
   let* z0 = i32_add z 1 in
@@ -46,7 +47,7 @@ type list_t (t : Type0) =
 | ListCons : t -> list_t t -> list_t t
 | ListNil : list_t t
 
-(** [paper::list_nth_mut] *)
+(** [paper::list_nth_mut]: forward function *)
 let rec list_nth_mut_fwd (t : Type0) (l : list_t t) (i : u32) : result t =
   begin match l with
   | ListCons x tl ->
@@ -56,7 +57,7 @@ let rec list_nth_mut_fwd (t : Type0) (l : list_t t) (i : u32) : result t =
   | ListNil -> Fail Failure
   end
 
-(** [paper::list_nth_mut] *)
+(** [paper::list_nth_mut]: backward function 0 *)
 let rec list_nth_mut_back
   (t : Type0) (l : list_t t) (i : u32) (ret : t) : result (list_t t) =
   begin match l with
@@ -70,14 +71,14 @@ let rec list_nth_mut_back
   | ListNil -> Fail Failure
   end
 
-(** [paper::sum] *)
+(** [paper::sum]: forward function *)
 let rec sum_fwd (l : list_t i32) : result i32 =
   begin match l with
   | ListCons x tl -> let* i = sum_fwd tl in i32_add x i
   | ListNil -> Return 0
   end
 
-(** [paper::test_nth] *)
+(** [paper::test_nth]: forward function *)
 let test_nth_fwd : result unit =
   let l = ListNil in
   let l0 = ListCons 3 l in
@@ -91,7 +92,7 @@ let test_nth_fwd : result unit =
 (** Unit test for [paper::test_nth] *)
 let _ = assert_norm (test_nth_fwd = Return ())
 
-(** [paper::call_choose] *)
+(** [paper::call_choose]: forward function *)
 let call_choose_fwd (p : (u32 & u32)) : result u32 =
   let (px, py) = p in
   let* pz = choose_fwd u32 true px py in
diff --git a/tests/fstar/misc/PoloniusList.fst b/tests/fstar/misc/PoloniusList.fst
index e2144487..79c86606 100644
--- a/tests/fstar/misc/PoloniusList.fst
+++ b/tests/fstar/misc/PoloniusList.fst
@@ -10,7 +10,7 @@ type list_t (t : Type0) =
 | ListCons : t -> list_t t -> list_t t
 | ListNil : list_t t
 
-(** [polonius_list::get_list_at_x] *)
+(** [polonius_list::get_list_at_x]: forward function *)
 let rec get_list_at_x_fwd (ls : list_t u32) (x : u32) : result (list_t u32) =
   begin match ls with
   | ListCons hd tl ->
@@ -18,7 +18,7 @@ let rec get_list_at_x_fwd (ls : list_t u32) (x : u32) : result (list_t u32) =
   | ListNil -> Return ListNil
   end
 
-(** [polonius_list::get_list_at_x] *)
+(** [polonius_list::get_list_at_x]: backward function 0 *)
 let rec get_list_at_x_back
   (ls : list_t u32) (x : u32) (ret : list_t u32) : result (list_t u32) =
   begin match ls with