ready to prove the correctness of 3-carry

This commit is contained in:
2025-06-22 06:58:57 +00:00
parent 1e3c1ea7ec
commit 6167816613
2 changed files with 111 additions and 1 deletions

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@ -282,6 +282,41 @@ Proof.
pose proof (Zlength_nonneg l1); lia.
Qed.
Lemma list_store_Z_list_append: forall (l: list Z) (i: Z) (val_prefix: Z) (val_full: Z),
0 <= i < Zlength l ->
list_store_Z_compact l val_full ->
list_store_Z (sublist 0 i l) val_prefix ->
list_store_Z (sublist 0 (i+1) l) (val_prefix + Znth i l 0 * UINT_MOD ^ i).
Proof.
intros.
assert ((sublist 0 (i + 1) l) = ((sublist 0 i l) ++ ((Znth i l 0) :: nil)))%list. {
pose proof (sublist_split 0 (i+1) i l).
pose proof (sublist_single i l 0).
rewrite <-H3; try rewrite <- Zlength_correct.
apply H2; try rewrite <- Zlength_correct.
lia. lia. lia.
}
rewrite H2.
pose proof (list_store_Z_concat (sublist 0 i l) (Znth i l 0 :: nil) (val_prefix) (Znth i l 0)).
assert (Zlength (sublist 0 i l) = i). {
rewrite Zlength_sublist0.
lia.
lia.
}
rewrite H4 in H3.
apply H3.
tauto.
unfold list_store_Z.
simpl.
split.
reflexivity.
split; try tauto.
apply list_within_bound_Znth.
lia.
unfold list_store_Z_compact in H0.
tauto.
Qed.
Lemma list_store_Z_split: forall (l1 l2: list Z) (n: Z),
list_store_Z (l1 ++ l2) n ->
list_store_Z l1 (n mod UINT_MOD ^ (Zlength l1)) /\

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@ -834,7 +834,82 @@ Proof.
Qed.
Lemma proof_of_mpn_add_n_entail_wit_3_1 : mpn_add_n_entail_wit_3_1.
Proof. Admitted.
Proof.
pre_process.
rewrite replace_Znth_app_r.
assert (l_a_3 = l_a_2). {
pose proof (list_store_Z_compact_reverse_injection l_a_3 l_a_2 val_a val_a).
specialize (H37 H13 H28).
apply H37.
reflexivity.
}
subst l_a_3.
assert (l_b_3 = l_b_2). {
pose proof (list_store_Z_compact_reverse_injection l_b_3 l_b_2 val_b val_b).
specialize (H37 H14 H24).
apply H37.
reflexivity.
}
subst l_b_3.
- Exists l_r_suffix'.
rewrite H29.
rewrite H18.
assert (i - i = 0) by lia.
rewrite H37; clear H37.
set (partial_result_1 := (unsigned_last_nbits (Znth i l_a_2 0 + cy) 32)).
set (partial_result_2 := (unsigned_last_nbits (partial_result_1 + Znth i l_b_2 0) 32)).
rewrite replace_Znth_nothing; try lia.
assert ((replace_Znth 0 partial_result_2 (a :: nil)) = partial_result_2 :: nil). {
unfold replace_Znth.
simpl.
reflexivity.
}
rewrite H37; clear H37.
Exists (l_r_prefix_2 ++ partial_result_2 :: nil).
Exists (val_r_prefix_2 + partial_result_2 * (UINT_MOD ^ i)).
Exists (val_b_prefix_2 + (Znth i l_b_2 0) * (UINT_MOD ^ i)).
Exists (val_a_prefix_2 + (Znth i l_a_2 0) * (UINT_MOD ^ i)).
Exists l_b_2 l_a_2.
entailer!.
+ admit.
+ pose proof (Zlength_app l_r_prefix_2 (partial_result_2 :: nil)).
assert (Zlength (partial_result_2 :: nil) = 1). {
unfold Zlength.
simpl.
reflexivity.
}
rewrite H38 in H37; clear H38.
rewrite H18 in H37.
apply H37.
+ pose proof (list_store_Z_concat l_r_prefix_2 (partial_result_2 :: nil) val_r_prefix_2 partial_result_2).
rewrite H18 in H37.
apply H37.
tauto.
unfold list_store_Z.
simpl.
split.
reflexivity.
split.
unfold partial_result_2.
unfold unsigned_last_nbits.
assert (2 ^ 32 = 4294967296). { nia. }
rewrite H38; clear H38.
apply Z.mod_pos_bound.
lia.
tauto.
+ pose proof (list_store_Z_list_append l_b_2 i val_b_prefix_2 val_b).
apply H37.
lia.
tauto.
tauto.
+ pose proof (list_store_Z_list_append l_a_2 i val_a_prefix_2 val_a).
apply H37.
lia.
tauto.
tauto.
- pose proof (Zlength_sublist0 i l_r_prefix_2).
lia.
Admitted.
Lemma proof_of_mpn_add_n_entail_wit_3_2 : mpn_add_n_entail_wit_3_2.
Proof. Admitted.