NB: This Coq documentation contains a revised version of the Coq implementation of these papers [1], [2], [3], [4], and is also the support for ongoing research. A partial archive (14/01/2001) is available at here. Drop us a line if you are interested in a complete, up-to-date archive.

Library begcd_mips_init

Require Import Epsilon.
Require Import ssreflect ssrbool eqtype.
Require Import Arith_ext ZArith_ext Lists_ext.
Require Import machine_int multi_int encode_decode integral_type nodup.
Import MachineInt.
Require Import mips_bipl mips_tactics mips_syntax.
Import mips_bipl.expr_m.
Require Import simu.
Import simu.simu_m.
Require Import begcd.
Require Import multi_zero_prg.
Require Import multi_negate_prg.
Require Import multi_is_even_prg multi_is_even_simu.
Require Import multi_sub_signed_unsigned_prg multi_sub_signed_unsigned_simu.
Require Import library_interfaces.

Local Open Scope machine_int_scope.
Local Open Scope zarith_ext_scope.
Local Open Scope heap_scope.
Local Open Scope nodup_scope.
Local Open Scope assoc_scope.

Definition init_mips rk ru rv ru1 ru2 ru3 rv1 rv2 rv3 rt1 rt2 rt3
  a0 a1 a2 a3 a4 a5 a6 :=
  ((multi_one_signed ru1 a0 a1 a2 a3 ;
    multi_zero_signed ru2 a0 a1 a2 a3 ;
    copy_signed_unsigned ru3 rk ru a0 a1 a2 a3 ;
    copy_signed_unsigned rv1 rk rv a0 a1 a2 a3 ;
    (multi_one_signed rv2 a0 a1 a2 a3 ;
     multi_sub_s_u rk rv2 ru a0 a1 a2 a3 a4 a5 a6) ;
    copy_signed_unsigned rv3 rk rv a0 a1 a2 a3) ;
   multi_is_even rk ru a0 ;
   while.ifte (beq a0 r0)
   (multi_zero_signed rt1 a0 a1 a2 a3 ;
    (multi_one_signed rt2 a0 a1 a2 a3 ;
     negate rt2 a0) ;
    (copy_signed_unsigned rt3 rk rv a0 a1 a2 a3 ;
      negate rt3 a0))
   (multi_one_signed rt1 a0 a1 a2 a3 ;
    multi_zero_signed rt2 a0 a1 a2 a3 ;
    copy_signed_unsigned rt3 rk ru a0 a1 a2 a3))%mips_cmd.

Definition uv_bound rk st u v s L :=
  0 < u2Z ([rk ]_ st)%mips_expr < 2 ^^ 31 /\
  L <> O /\
  L = Zabs_nat (u2Z ([rk ]_ st)%mips_expr) /\
  0 < ([u ]_ s)%seplog_expr < Zbeta (L - 1) /\
  0 < ([v ]_ s)%seplog_expr < Zbeta (L - 1).

Lemma fwd_sim_begcd_init : forall vu vv g u v u1 u2 u3 v1 v2 v3 t1 t2 t3 L
  rk rg ru rv ru1 ru2 ru3 rv1 rv2 rv3 rt1 rt2 rt3 a0 a1 a2 a3 a4 a5 a6,
  nodup(g,u,v,u1,u2,u3,v1,v2,v3,t1,t2,t3) ->
  nodup(rk,rg,ru,rv,ru1,ru2,ru3,rv1,rv2,rv3,rt1,rt2,rt3,a0,a1,a2,a3,a4,a5,a6,r0) ->
  0 < vu -> 0 < vv ->
  fwd_sim (state_mint
    (g |=> unsign rk rg \U+ (u |=> unsign rk ru \U+ (v |=> unsign rk rv \U+
    (u1 |=> signed L ru1 \U+ (u2 |=> signed L ru2 \U+ (u3 |=> signed L ru3 \U+
    (v1 |=> signed L rv1 \U+ (v2 |=> signed L rv2 \U+ (v3 |=> signed L rv3 \U+
    (t1 |=> signed L rt1 \U+ (t2 |=> signed L rt2 \U+ t3 |=> signed L rt3))))))))))))
  (fun s st _ => (EGCD.C2 vu vv u v g s /\ EGCD.C3 vu vv u v g s) /\ uv_bound rk st u v s L)
  (EGCD.TAOCP.init u v u1 u2 u3 v1 v2 v3 t1 t2 t3)
  (init_mips rk ru rv ru1 ru2 ru3 rv1 rv2 rv3 rt1 rt2 rt3 a0 a1 a2 a3 a4 a5 a6).
Proof.
move=> vu vv g u v u1 u2 u3 v1 v2 v3 t1 t2 t3 L
rk rg ru rv ru1 ru2 ru3 rv1 rv2 rv3 rt1 rt2 rt3 a0 a1 a2 a3 a4 a5 a6
Hvars Hset Hvu Hvv.
rewrite /EGCD.TAOCP.init /init_mips.
apply fwd_sim_seq with (fun s st h => (EGCD.C2 vu vv u v g s /\ EGCD.C3 vu vv u v g s /\
    EGCD.uivi_init u v u1 u2 u3 v1 v2 v3 s) /\ uv_bound rk st u v s L) => //.
- rewrite /rela_hoare => s st h Hcond s' exec_pseudo st' h' exec_asm; split.
  move: (EGCD.TAOCP.begcd_verif_init0 _ _ _ _ _ _ _ _ _ _ _ _ _ _ Hvars Hvu Hvv).
  move/syntax_m.seplog_m.hoare_prop_m.soundness.
  rewrite /while.hoare_semantics.
  case/( _ _ syntax_m.seplog_m.assert_m.heap.emp (proj1 Hcond)) => _.
  by move/(_ _ _ exec_pseudo).
- rewrite /uv_bound.
  have <- : ([rk]_st = [rk]_ st')%mips_expr.
    mips_syntax.Reg_unchanged. rewrite [mips_frame.modified_regs _]/=; by Nodup_not_In.
  local_Var_unchanged u s.
  local_Var_unchanged v s.
  rewrite /uv_bound in Hcond; tauto.
- apply fwd_sim_seq with (fun s st _ => (EGCD.C2 vu vv u v g s /\
    EGCD.C3 vu vv u v g s) /\ uv_bound rk st u v s L) => //.
  + rewrite /rela_hoare => s st h Hcond s' exec_pseudo st' h' exec_asm; split.
    * rewrite /EGCD.C2 / EGCD.C3 in Hcond *.
      rewrite /=.
      local_Var_unchanged u s.
      local_Var_unchanged v s.
      local_Var_unchanged g s.
      tauto.
    * rewrite /uv_bound.
      have <- : ([rk]_st = [rk]_ st')%mips_expr.
        mips_syntax.Reg_unchanged. rewrite [mips_frame.modified_regs _]/=; by Nodup_not_In.
      local_Var_unchanged u s.
      local_Var_unchanged v s.
      tauto.
  + assoc_put_in_front u1.
    apply pfwd_sim_fwd_sim; last by apply safe_termination_one_signed; Nodup_nodup r0.
    apply pfwd_sim_one_signed.
    - by Nodup_nodup r0.
    - Disj_f_cdom2list Permutation_mints_regs.
      Disj_remove_dup. apply: nodup.nodup_disj; rewrite [List.app _ _]/=; by Nodup_nodup r0.
    - apply/seq_ext.inP.
      Not_In_dom2list; by Nodup_not_In.
    - apply/seq_ext.inP.
      Not_In_dom2list.
      apply not_In_mint_ptr. simpl mint_ptr. simpl List.map. by Nodup_not_In.
  apply fwd_sim_seq with (fun s st _ => (EGCD.C2 vu vv u v g s /\
    EGCD.C3 vu vv u v g s) /\ uv_bound rk st u v s L) => //.
  + rewrite /rela_hoare => s st h Hcond s' exec_pseudo st' h' exec_asm; split.
    * rewrite /EGCD.C2 / EGCD.C3 in Hcond *.
      rewrite /=.
      local_Var_unchanged u s.
      local_Var_unchanged v s.
      local_Var_unchanged g s.
      tauto.
    * rewrite /uv_bound.
      have <- : ([rk]_st = [rk]_ st')%mips_expr.
        mips_syntax.Reg_unchanged. rewrite [mips_frame.modified_regs _]/=; by Nodup_not_In.
      local_Var_unchanged u s.
      local_Var_unchanged v s.
      tauto.
  + assoc_put_in_front u2.
    apply pfwd_sim_fwd_sim; last by apply safe_termination_zero_signed; Nodup_nodup r0.
    apply pfwd_sim_zero_signed.
    - by Nodup_nodup r0.
    - Disj_f_cdom2list Permutation_mints_regs.
      Disj_remove_dup. apply: nodup.nodup_disj; rewrite [List.app _ _]/=; by Nodup_nodup r0.
    - apply/seq_ext.inP.
      Not_In_dom2list; by Nodup_not_In.
    - apply/seq_ext.inP.
      Not_In_dom2list.
      apply not_In_mint_ptr. simpl mint_ptr. simpl List.map. by Nodup_not_In.
  apply fwd_sim_seq with (fun s st _ => (EGCD.C2 vu vv u v g s /\
    EGCD.C3 vu vv u v g s) /\ uv_bound rk st u v s L) => //.
  + rewrite /rela_hoare => s st h Hcond s' exec_pseudo st' h' exec_asm; split.
    * rewrite /EGCD.C2 / EGCD.C3 in Hcond *.
      rewrite /=.
      local_Var_unchanged u s.
      local_Var_unchanged v s.
      local_Var_unchanged g s.
      tauto.
    * rewrite /uv_bound.
      have <- : ([rk]_st = [rk]_ st')%mips_expr.
        mips_syntax.Reg_unchanged. rewrite [mips_frame.modified_regs _]/=; by Nodup_not_In.
      local_Var_unchanged u s.
      local_Var_unchanged v s.
      tauto.
  + assoc_put_in_front u3.
    assoc_put_in_front u.
    apply pfwd_sim_fwd_sim; last by apply safe_termination_copy_signed_unsigned; Nodup_nodup r0.
    apply pfwd_sim_copy_signed_unsigned.
    - by Nodup_nodup r0.
    - Disj_f_cdom2list Permutation_mints_regs.
      Disj_remove_dup. apply: nodup.nodup_disj; rewrite [List.app _ _]/=; by Nodup_nodup r0.
    - apply/seq_ext.inP.
      Not_In_dom2list.
      apply not_In_mint_ptr. simpl map. simpl mint_ptr. by Nodup_not_In.
    - apply/seq_ext.inP.
      Not_In_dom2list.
      apply not_In_mint_ptr. simpl mint_ptr. simpl List.map. by Nodup_not_In.
  apply fwd_sim_seq with (fun s st _ => (EGCD.C2 vu vv u v g s /\
    EGCD.C3 vu vv u v g s) /\ uv_bound rk st u v s L) => //.
  + rewrite /rela_hoare => s st h Hcond s' exec_pseudo st' h' exec_asm; split.
    * rewrite /EGCD.C2 / EGCD.C3 in Hcond *.
      rewrite /=.
      local_Var_unchanged u s.
      local_Var_unchanged v s.
      local_Var_unchanged g s.
      tauto.
    * rewrite /uv_bound.
      have <- : ([rk]_st = [rk]_ st')%mips_expr.
        mips_syntax.Reg_unchanged. rewrite [mips_frame.modified_regs _]/=; by Nodup_not_In.
      local_Var_unchanged u s.
      local_Var_unchanged v s.
      tauto.
  + assoc_put_in_front v1.
    assoc_put_in_front v.
    apply pfwd_sim_fwd_sim; last by apply safe_termination_copy_signed_unsigned; Nodup_nodup r0.
    apply pfwd_sim_copy_signed_unsigned.
    - by Nodup_nodup r0.
    - Disj_f_cdom2list Permutation_mints_regs.
      Disj_remove_dup. apply: nodup.nodup_disj; rewrite [List.app _ _]/=; by Nodup_nodup r0.
    - apply/seq_ext.inP.
      Not_In_dom2list.
      apply not_In_mint_ptr. simpl map. simpl mint_ptr. by Nodup_not_In.
    - apply/seq_ext.inP.
      Not_In_dom2list.
      apply not_In_mint_ptr. simpl mint_ptr. simpl List.map. by Nodup_not_In.
  apply fwd_sim_seq with (fun s st _ => (EGCD.C2 vu vv u v g s /\
    EGCD.C3 vu vv u v g s) /\ uv_bound rk st u v s L) => //.
  + rewrite /rela_hoare => s st h Hcond s' exec_pseudo st' h' exec_asm; split.
    * rewrite /EGCD.C2 / EGCD.C3 in Hcond *.
      rewrite /=.
      local_Var_unchanged u s.
      local_Var_unchanged v s.
      local_Var_unchanged g s.
      tauto.
    * rewrite /uv_bound.
      have <- : ([rk]_st = [rk]_ st')%mips_expr.
        mips_syntax.Reg_unchanged. rewrite [mips_frame.modified_regs _]/=; by Nodup_not_In.
      local_Var_unchanged u s.
      local_Var_unchanged v s.
      tauto.
  apply fwd_sim_pcode_equiv with (v2 <- nat_e 1 ; v2 <- var_e v2 .-e var_e u)%seplog_expr%seplog_cmd; last by apply equivalent_pseudo_code_example2; Nodup_neq.
  apply fwd_sim_seq with (fun s st _ => [rk ]_ st <> zero32 /\
    u2Z ([rk ]_ st) < 2 ^^ 31 /\
    L <> O /\
    L = Zabs_nat (u2Z ([rk ]_ st)) /\
    Zabs ([v2 ]_ s)%seplog_expr < Zbeta (L - 1) /\
    0 <= ([u ]_ s)%seplog_expr < Zbeta (L - 1))%mips_expr => //.
  + rewrite /rela_hoare => s st h Hcond s' exec_pseudo st' h' exec_asm.
    rewrite /uv_bound in Hcond.
    have <- : ([rk]_st = [rk]_ st')%mips_expr.
      mips_syntax.Reg_unchanged. rewrite [mips_frame.modified_regs _]/=; by Nodup_not_In.
    local_Var_unchanged u s.
    move/syntax_m.seplog_m.semop_prop_m.exec_cmd0_inv : exec_pseudo.
    case/syntax_m.seplog_m.exec0_assign_inv => _ ->.
    repeat syntax_m.seplog_m.assert_m.expr_m.Store_upd.
    split; first by move=> abs; rewrite abs u2Z_Z2u // in Hcond; omega.
    repeat (split; first by tauto).
    split; first by move: (Zbeta_0' L) => /= ?; omega.
    omega.
  + assoc_put_in_front v2.
    apply pfwd_sim_fwd_sim; last by apply safe_termination_one_signed; Nodup_nodup r0.
    apply pfwd_sim_one_signed.
    - by Nodup_nodup r0.
    - Disj_f_cdom2list Permutation_mints_regs.
      Disj_remove_dup. apply: nodup.nodup_disj; rewrite [List.app _ _]/=; by Nodup_nodup r0.
    - apply/seq_ext.inP.
      Not_In_dom2list.
      by Nodup_not_In.
    - apply/seq_ext.inP.
      Not_In_dom2list.
      apply not_In_mint_ptr. simpl mint_ptr. simpl List.map. by Nodup_not_In.
  assoc_put_in_front u.
  assoc_put_in_front v2.
  apply pfwd_sim_fwd_sim; last by apply safe_termination_multi_sub_s_u; Nodup_nodup r0.
  apply pfwd_sim_multi_sub_s_u_wo_overflow.
    - rewrite [Equality.sort _]/= in Hvars *. by Nodup_nodup O.
    - by Nodup_nodup r0.
    - Disj_f_cdom2list Permutation_mints_regs.
      Disj_remove_dup. apply: nodup.nodup_disj; rewrite [List.app _ _]/=; by Nodup_nodup r0.
    - apply/seq_ext.inP.
      Not_In_dom2list; by Nodup_not_In.
    - apply/seq_ext.inP.
      Not_In_dom2list; by Nodup_not_In.
    - apply/seq_ext.inP.
      Not_In_dom2list.
      apply not_In_mint_ptr. rewrite [mint_ptr _]/= [List.map _ _]/=. by Nodup_not_In.
    - apply/seq_ext.inP.
      Not_In_dom2list.
      apply not_In_mint_ptr. rewrite [mint_ptr _]/= [List.map _ _]/=. by Nodup_not_In.
  assoc_put_in_front v3.
  assoc_put_in_front v.
  apply pfwd_sim_fwd_sim; last by apply safe_termination_copy_signed_unsigned; Nodup_nodup r0.
  apply pfwd_sim_copy_signed_unsigned.
  - by Nodup_nodup r0.
  - Disj_f_cdom2list Permutation_mints_regs.
    Disj_remove_dup. apply: nodup.nodup_disj; rewrite [List.app _ _]/=; by Nodup_nodup r0.
  - apply/seq_ext.inP.
    Not_In_dom2list.
    apply not_In_mint_ptr. simpl map. simpl mint_ptr. by Nodup_not_In.
  - apply/seq_ext.inP.
    Not_In_dom2list.
    apply not_In_mint_ptr. simpl mint_ptr. simpl List.map. by Nodup_not_In.
apply fwd_sim_ifte => //.
- rewrite /inv_R => s st h [s_st_h Hcond] st' h' exec_asm; split.
  + eapply state_mint_invariant; [idtac | idtac | apply s_st_h | apply exec_asm] => //.
    Disj_f_cdom2list Permutation_mints_regs.
    rewrite [mips_frame.modified_regs _]/=.
    Disj_remove_dup.
    apply: nodup.nodup_disj. rewrite [List.app _ _]/=. by Nodup_nodup r0.
  + rewrite /uv_bound.
    have <- : ([rk]_st = [rk]_ st')%mips_expr.
      mips_syntax.Reg_unchanged. rewrite [mips_frame.modified_regs _]/=; by Nodup_not_In.
    tauto.
- assoc_put_in_front u.
  apply fwd_sim_b_multi_is_even.
  + by Nodup_nodup r0.
  + Disj_f_cdom2list Permutation_mints_regs.
    Disj_remove_dup. apply: nodup.nodup_disj; rewrite [List.app _ _]/=; by Nodup_nodup r0.
    apply/seq_ext.inP.
    Not_In_dom2list; by Nodup_not_In.
    apply/seq_ext.inP.
    Not_In_dom2list.
    apply not_In_mint_ptr. rewrite [mint_ptr _]/= [List.map _ _]/=. by Nodup_not_In.
- apply fwd_sim_seq with (fun s st _ => ((EGCD.C2 vu vv u v g s /\
    EGCD.C3 vu vv u v g s /\ EGCD.uivi_init u v u1 u2 u3 v1 v2 v3 s) /\
    uv_bound rk st u v s L) /\
    ([var_e u mode nat_e 2 =e nat_e 1 ]b_ s)%seplog_expr) => //.
  + rewrite /rela_hoare => s st h Hcond s' exec_pseudo st' h' exec_asm.
    move/syntax_m.seplog_m.semop_prop_m.exec_cmd0_inv : exec_pseudo.
    case/syntax_m.seplog_m.exec0_assign_inv => _ ->.
    rewrite /EGCD.C2 /EGCD.C3 /EGCD.uivi_init /uv_bound in Hcond *.
    simpl.
    repeat syntax_m.seplog_m.assert_m.expr_m.Store_upd.
    have <- : ([rk]_st = [rk]_ st')%mips_expr.
      mips_syntax.Reg_unchanged. rewrite [mips_frame.modified_regs _]/=; by Nodup_not_In.
    tauto.
  + assoc_put_in_front t1.
    apply pfwd_sim_fwd_sim; last by apply safe_termination_zero_signed; Nodup_nodup r0.
    apply pfwd_sim_zero_signed.
    - by Nodup_nodup r0.
    - Disj_f_cdom2list Permutation_mints_regs.
      Disj_remove_dup. apply: nodup.nodup_disj; rewrite [List.app _ _]/=; by Nodup_nodup r0.
    - apply/seq_ext.inP.
      Not_In_dom2list.
      by Nodup_not_In.
    - apply/seq_ext.inP.
      Not_In_dom2list.
      apply not_In_mint_ptr. simpl mint_ptr. simpl List.map. by Nodup_not_In.
- apply fwd_sim_seq with (fun s st _ =>
      ((EGCD.C2 vu vv u v g s /\
        EGCD.C3 vu vv u v g s /\ EGCD.uivi_init u v u1 u2 u3 v1 v2 v3 s) /\
       uv_bound rk st u v s L) /\
      ([var_e u mode nat_e 2 =e nat_e 1 ]b_ s)%seplog_expr) => //.
  + rewrite /rela_hoare => s st h Hcond s' exec_pseudo st' h' exec_asm.
    move/syntax_m.seplog_m.semop_prop_m.exec_cmd0_inv : exec_pseudo.
    case/syntax_m.seplog_m.exec0_assign_inv => _ ->.
    rewrite /EGCD.C2 /EGCD.C3 /EGCD.uivi_init /uv_bound in Hcond *.
    simpl.
    repeat syntax_m.seplog_m.assert_m.expr_m.Store_upd.
    have <- : ([rk]_st = [rk]_ st')%mips_expr.
      mips_syntax.Reg_unchanged. rewrite [mips_frame.modified_regs _]/=; by Nodup_not_In.
    tauto.
  apply fwd_sim_pcode_equiv with (t2 <- nat_e 1 ; t2 <- .--e (var_e t2))%seplog_expr%seplog_cmd; last first.
eapply equivalent_pseudo_code_trans; by [apply equivalent_pseudo_code_example3 | apply equivalent_pseudo_code_example_assign].
apply fwd_sim_seq with (fun s st _ => ((EGCD.C2 vu vv u v g s /\
  EGCD.uivi_init u v u1 u2 u3 v1 v2 v3 s) /\ uv_bound rk st u v s L)) => //.
- rewrite /rela_hoare => s st h Hcond s' exec_pseudo st' h' exec_asm.
  move/syntax_m.seplog_m.semop_prop_m.exec_cmd0_inv : exec_pseudo.
  case/syntax_m.seplog_m.exec0_assign_inv => _ ->.
  rewrite /EGCD.C2 /EGCD.uivi_init /uv_bound in Hcond *.
  repeat syntax_m.seplog_m.assert_m.expr_m.Store_upd.
  have <- : ([rk]_st = [rk]_ st')%mips_expr.
    mips_syntax.Reg_unchanged. rewrite [mips_frame.modified_regs _]/=; by Nodup_not_In.
  tauto.
- assoc_put_in_front t2.
  apply pfwd_sim_fwd_sim; last by apply safe_termination_one_signed; Nodup_nodup r0.
  apply pfwd_sim_one_signed.
  - by Nodup_nodup r0.
  - Disj_f_cdom2list Permutation_mints_regs.
    Disj_remove_dup. apply: nodup.nodup_disj; rewrite [List.app _ _]/=; by Nodup_nodup r0.
  - apply/seq_ext.inP.
    Not_In_dom2list; by Nodup_not_In.
  - apply/seq_ext.inP.
    Not_In_dom2list.
    apply not_In_mint_ptr. simpl mint_ptr. simpl List.map. by Nodup_not_In.
- assoc_put_in_front t2.
  apply pfwd_sim_fwd_sim; last by apply safe_termination_negate; Nodup_nodup r0.
  apply pfwd_sim_negate.
  - by Nodup_nodup r0.
  - Disj_f_cdom2list Permutation_mints_regs.
    Disj_remove_dup. apply: nodup.nodup_disj; rewrite [List.app _ _]/=; by Nodup_nodup r0.
  - apply/seq_ext.inP.
    Not_In_dom2list; by Nodup_not_In.
  - apply/seq_ext.inP.
    Not_In_dom2list.
    apply not_In_mint_ptr. simpl mint_ptr. simpl List.map. by Nodup_not_In.
- apply fwd_sim_pcode_equiv with (t3 <- var_e v ; t3 <- .--e (var_e t3))%seplog_expr%seplog_cmd; last first.
  eapply equivalent_pseudo_code_trans; by [apply equivalent_pseudo_code_example3 | apply equivalent_pseudo_code_example_assign].
  apply fwd_sim_seq with (fun s st _ =>
      ((EGCD.C2 vu vv u v g s /\ EGCD.uivi_init u v u1 u2 u3 v1 v2 v3 s) /\
       uv_bound rk st u v s L)) => //.
  - rewrite /rela_hoare => s st h Hcond s' exec_pseudo st' h' exec_asm.
    move/syntax_m.seplog_m.semop_prop_m.exec_cmd0_inv : exec_pseudo.
    case/syntax_m.seplog_m.exec0_assign_inv => _ ->.
    rewrite /EGCD.C2 /EGCD.uivi_init /uv_bound in Hcond *.
    repeat syntax_m.seplog_m.assert_m.expr_m.Store_upd.
    have <- : ([rk]_st = [rk]_ st')%mips_expr.
      mips_syntax.Reg_unchanged. rewrite [mips_frame.modified_regs _]/=; by Nodup_not_In.
    tauto.
  - assoc_put_in_front t3.
    assoc_put_in_front v.
    apply pfwd_sim_fwd_sim; last by apply safe_termination_copy_signed_unsigned; Nodup_nodup r0.
    apply pfwd_sim_copy_signed_unsigned.
    - by Nodup_nodup r0.
    - Disj_f_cdom2list Permutation_mints_regs.
      Disj_remove_dup. apply: nodup.nodup_disj; rewrite [List.app _ _]/=; by Nodup_nodup r0.
    - apply/seq_ext.inP.
      Not_In_dom2list.
      apply not_In_mint_ptr. simpl mint_ptr. simpl List.map. by Nodup_not_In.
    - apply/seq_ext.inP.
      Not_In_dom2list.
      apply not_In_mint_ptr. simpl mint_ptr. simpl List.map. by Nodup_not_In.
- assoc_put_in_front t3.
  apply pfwd_sim_fwd_sim; last by apply safe_termination_negate; Nodup_nodup r0.
  apply pfwd_sim_negate.
  - by Nodup_nodup r0.
  - Disj_f_cdom2list Permutation_mints_regs.
    Disj_remove_dup. apply: nodup.nodup_disj; rewrite [List.app _ _]/=; by Nodup_nodup r0.
  - apply/seq_ext.inP.
    Not_In_dom2list; by Nodup_not_In.
  - apply/seq_ext.inP.
    Not_In_dom2list.
    apply not_In_mint_ptr. simpl mint_ptr. simpl List.map. by Nodup_not_In.
apply fwd_sim_seq with (fun s st _ =>
      ((EGCD.C2 vu vv u v g s /\ EGCD.uivi_init u v u1 u2 u3 v1 v2 v3 s) /\
       uv_bound rk st u v s L) ) => //.
- rewrite /rela_hoare => s st h Hcond s' exec_pseudo st' h' exec_asm.
  move/syntax_m.seplog_m.semop_prop_m.exec_cmd0_inv : exec_pseudo.
  case/syntax_m.seplog_m.exec0_assign_inv => _ ->.
  rewrite /EGCD.C2 /EGCD.uivi_init /uv_bound in Hcond *.
  repeat syntax_m.seplog_m.assert_m.expr_m.Store_upd.
  have <- : ([rk]_st = [rk]_ st')%mips_expr.
    mips_syntax.Reg_unchanged. rewrite [mips_frame.modified_regs _]/=; by Nodup_not_In.
  tauto.
- assoc_put_in_front t1.
  apply pfwd_sim_fwd_sim; last by apply safe_termination_one_signed; Nodup_nodup r0.
  apply pfwd_sim_one_signed.
  - by Nodup_nodup r0.
  - Disj_f_cdom2list Permutation_mints_regs.
    Disj_remove_dup. apply: nodup.nodup_disj; rewrite [List.app _ _]/=; by Nodup_nodup r0.
  - apply/seq_ext.inP.
    Not_In_dom2list. by Nodup_not_In.
  - apply/seq_ext.inP.
    Not_In_dom2list.
    apply not_In_mint_ptr. simpl mint_ptr. simpl List.map. by Nodup_not_In.
apply fwd_sim_seq with (fun s st _ =>
      (EGCD.C2 vu vv u v g s /\ EGCD.uivi_init u v u1 u2 u3 v1 v2 v3 s) /\
      uv_bound rk st u v s L) => //.
- rewrite /rela_hoare => s st h Hcond s' exec_pseudo st' h' exec_asm.
  move/syntax_m.seplog_m.semop_prop_m.exec_cmd0_inv : exec_pseudo.
  case/syntax_m.seplog_m.exec0_assign_inv => _ ->.
  rewrite /EGCD.C2 /EGCD.uivi_init /uv_bound in Hcond *.
  repeat syntax_m.seplog_m.assert_m.expr_m.Store_upd.
  have <- : ([rk]_st = [rk]_ st')%mips_expr.
    mips_syntax.Reg_unchanged. rewrite [mips_frame.modified_regs _]/=; by Nodup_not_In.
  tauto.
- assoc_put_in_front t2.
  apply pfwd_sim_fwd_sim; last by apply safe_termination_zero_signed; Nodup_nodup r0.
  apply pfwd_sim_zero_signed.
  - by Nodup_nodup r0.
  - Disj_f_cdom2list Permutation_mints_regs.
    Disj_remove_dup. apply: nodup.nodup_disj; rewrite [List.app _ _]/=; by Nodup_nodup r0.
  - apply/seq_ext.inP.
    Not_In_dom2list. by Nodup_not_In.
  - apply/seq_ext.inP.
    Not_In_dom2list.
    apply not_In_mint_ptr. simpl mint_ptr. simpl List.map. by Nodup_not_In.
- assoc_put_in_front t3.
  assoc_put_in_front u.
  apply pfwd_sim_fwd_sim; last by apply safe_termination_copy_signed_unsigned; Nodup_nodup r0.
  apply pfwd_sim_copy_signed_unsigned.
  - by Nodup_nodup r0.
  - Disj_f_cdom2list Permutation_mints_regs.
    Disj_remove_dup. apply: nodup.nodup_disj; rewrite [List.app _ _]/=; by Nodup_nodup r0.
  - apply/seq_ext.inP.
    Not_In_dom2list.
    apply not_In_mint_ptr. simpl mint_ptr. simpl List.map. by Nodup_not_In.
  - apply/seq_ext.inP.
    Not_In_dom2list.
    apply not_In_mint_ptr. simpl mint_ptr. simpl List.map. by Nodup_not_In.
Qed.