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Diffstat (limited to 'plugins/omega/PreOmega.v')
-rw-r--r-- | plugins/omega/PreOmega.v | 445 |
1 files changed, 445 insertions, 0 deletions
diff --git a/plugins/omega/PreOmega.v b/plugins/omega/PreOmega.v new file mode 100644 index 00000000..a5a085a9 --- /dev/null +++ b/plugins/omega/PreOmega.v @@ -0,0 +1,445 @@ +Require Import Arith Max Min ZArith_base NArith Nnat. + +Open Local Scope Z_scope. + + +(** * zify: the Z-ification tactic *) + +(* This tactic searches for nat and N and positive elements in the goal and + translates everything into Z. It is meant as a pre-processor for + (r)omega; for instance a positivity hypothesis is added whenever + - a multiplication is encountered + - an atom is encountered (that is a variable or an unknown construct) + + Recognized relations (can be handled as deeply as allowed by setoid rewrite): + - { eq, le, lt, ge, gt } on { Z, positive, N, nat } + + Recognized operations: + - on Z: Zmin, Zmax, Zabs, Zsgn are translated in term of <= < = + - on nat: + * - S O pred min max nat_of_P nat_of_N Zabs_nat + - on positive: Zneg Zpos xI xO xH + * - Psucc Ppred Pmin Pmax P_of_succ_nat + - on N: N0 Npos + * - Nsucc Nmin Nmax N_of_nat Zabs_N +*) + + + + +(** I) translation of Zmax, Zmin, Zabs, Zsgn into recognized equations *) + +Ltac zify_unop_core t thm a := + (* Let's introduce the specification theorem for t *) + let H:= fresh "H" in assert (H:=thm a); + (* Then we replace (t a) everywhere with a fresh variable *) + let z := fresh "z" in set (z:=t a) in *; clearbody z. + +Ltac zify_unop_var_or_term t thm a := + (* If a is a variable, no need for aliasing *) + let za := fresh "z" in + (rename a into za; rename za into a; zify_unop_core t thm a) || + (* Otherwise, a is a complex term: we alias it. *) + (remember a as za; zify_unop_core t thm za). + +Ltac zify_unop t thm a := + (* if a is a scalar, we can simply reduce the unop *) + let isz := isZcst a in + match isz with + | true => simpl (t a) in * + | _ => zify_unop_var_or_term t thm a + end. + +Ltac zify_unop_nored t thm a := + (* in this version, we don't try to reduce the unop (that can be (Zplus x)) *) + let isz := isZcst a in + match isz with + | true => zify_unop_core t thm a + | _ => zify_unop_var_or_term t thm a + end. + +Ltac zify_binop t thm a b:= + (* works as zify_unop, except that we should be careful when + dealing with b, since it can be equal to a *) + let isza := isZcst a in + match isza with + | true => zify_unop (t a) (thm a) b + | _ => + let za := fresh "z" in + (rename a into za; rename za into a; zify_unop_nored (t a) (thm a) b) || + (remember a as za; match goal with + | H : za = b |- _ => zify_unop_nored (t za) (thm za) za + | _ => zify_unop_nored (t za) (thm za) b + end) + end. + +Ltac zify_op_1 := + match goal with + | |- context [ Zmax ?a ?b ] => zify_binop Zmax Zmax_spec a b + | H : context [ Zmax ?a ?b ] |- _ => zify_binop Zmax Zmax_spec a b + | |- context [ Zmin ?a ?b ] => zify_binop Zmin Zmin_spec a b + | H : context [ Zmin ?a ?b ] |- _ => zify_binop Zmin Zmin_spec a b + | |- context [ Zsgn ?a ] => zify_unop Zsgn Zsgn_spec a + | H : context [ Zsgn ?a ] |- _ => zify_unop Zsgn Zsgn_spec a + | |- context [ Zabs ?a ] => zify_unop Zabs Zabs_spec a + | H : context [ Zabs ?a ] |- _ => zify_unop Zabs Zabs_spec a + end. + +Ltac zify_op := repeat zify_op_1. + + + + + +(** II) Conversion from nat to Z *) + + +Definition Z_of_nat' := Z_of_nat. + +Ltac hide_Z_of_nat t := + let z := fresh "z" in set (z:=Z_of_nat t) in *; + change Z_of_nat with Z_of_nat' in z; + unfold z in *; clear z. + +Ltac zify_nat_rel := + match goal with + (* I: equalities *) + | H : (@eq nat ?a ?b) |- _ => generalize (inj_eq _ _ H); clear H; intro H + | |- (@eq nat ?a ?b) => apply (inj_eq_rev a b) + | H : context [ @eq nat ?a ?b ] |- _ => rewrite (inj_eq_iff a b) in H + | |- context [ @eq nat ?a ?b ] => rewrite (inj_eq_iff a b) + (* II: less than *) + | H : (lt ?a ?b) |- _ => generalize (inj_lt _ _ H); clear H; intro H + | |- (lt ?a ?b) => apply (inj_lt_rev a b) + | H : context [ lt ?a ?b ] |- _ => rewrite (inj_lt_iff a b) in H + | |- context [ lt ?a ?b ] => rewrite (inj_lt_iff a b) + (* III: less or equal *) + | H : (le ?a ?b) |- _ => generalize (inj_le _ _ H); clear H; intro H + | |- (le ?a ?b) => apply (inj_le_rev a b) + | H : context [ le ?a ?b ] |- _ => rewrite (inj_le_iff a b) in H + | |- context [ le ?a ?b ] => rewrite (inj_le_iff a b) + (* IV: greater than *) + | H : (gt ?a ?b) |- _ => generalize (inj_gt _ _ H); clear H; intro H + | |- (gt ?a ?b) => apply (inj_gt_rev a b) + | H : context [ gt ?a ?b ] |- _ => rewrite (inj_gt_iff a b) in H + | |- context [ gt ?a ?b ] => rewrite (inj_gt_iff a b) + (* V: greater or equal *) + | H : (ge ?a ?b) |- _ => generalize (inj_ge _ _ H); clear H; intro H + | |- (ge ?a ?b) => apply (inj_ge_rev a b) + | H : context [ ge ?a ?b ] |- _ => rewrite (inj_ge_iff a b) in H + | |- context [ ge ?a ?b ] => rewrite (inj_ge_iff a b) + end. + +Ltac zify_nat_op := + match goal with + (* misc type conversions: positive/N/Z to nat *) + | H : context [ Z_of_nat (nat_of_P ?a) ] |- _ => rewrite <- (Zpos_eq_Z_of_nat_o_nat_of_P a) in H + | |- context [ Z_of_nat (nat_of_P ?a) ] => rewrite <- (Zpos_eq_Z_of_nat_o_nat_of_P a) + | H : context [ Z_of_nat (nat_of_N ?a) ] |- _ => rewrite (Z_of_nat_of_N a) in H + | |- context [ Z_of_nat (nat_of_N ?a) ] => rewrite (Z_of_nat_of_N a) + | H : context [ Z_of_nat (Zabs_nat ?a) ] |- _ => rewrite (inj_Zabs_nat a) in H + | |- context [ Z_of_nat (Zabs_nat ?a) ] => rewrite (inj_Zabs_nat a) + + (* plus -> Zplus *) + | H : context [ Z_of_nat (plus ?a ?b) ] |- _ => rewrite (inj_plus a b) in H + | |- context [ Z_of_nat (plus ?a ?b) ] => rewrite (inj_plus a b) + + (* min -> Zmin *) + | H : context [ Z_of_nat (min ?a ?b) ] |- _ => rewrite (inj_min a b) in H + | |- context [ Z_of_nat (min ?a ?b) ] => rewrite (inj_min a b) + + (* max -> Zmax *) + | H : context [ Z_of_nat (max ?a ?b) ] |- _ => rewrite (inj_max a b) in H + | |- context [ Z_of_nat (max ?a ?b) ] => rewrite (inj_max a b) + + (* minus -> Zmax (Zminus ... ...) 0 *) + | H : context [ Z_of_nat (minus ?a ?b) ] |- _ => rewrite (inj_minus a b) in H + | |- context [ Z_of_nat (minus ?a ?b) ] => rewrite (inj_minus a b) + + (* pred -> minus ... -1 -> Zmax (Zminus ... -1) 0 *) + | H : context [ Z_of_nat (pred ?a) ] |- _ => rewrite (pred_of_minus a) in H + | |- context [ Z_of_nat (pred ?a) ] => rewrite (pred_of_minus a) + + (* mult -> Zmult and a positivity hypothesis *) + | H : context [ Z_of_nat (mult ?a ?b) ] |- _ => + let H:= fresh "H" in + assert (H:=Zle_0_nat (mult a b)); rewrite (inj_mult a b) in * + | |- context [ Z_of_nat (mult ?a ?b) ] => + let H:= fresh "H" in + assert (H:=Zle_0_nat (mult a b)); rewrite (inj_mult a b) in * + + (* O -> Z0 *) + | H : context [ Z_of_nat O ] |- _ => simpl (Z_of_nat O) in H + | |- context [ Z_of_nat O ] => simpl (Z_of_nat O) + + (* S -> number or Zsucc *) + | H : context [ Z_of_nat (S ?a) ] |- _ => + let isnat := isnatcst a in + match isnat with + | true => simpl (Z_of_nat (S a)) in H + | _ => rewrite (inj_S a) in H + end + | |- context [ Z_of_nat (S ?a) ] => + let isnat := isnatcst a in + match isnat with + | true => simpl (Z_of_nat (S a)) + | _ => rewrite (inj_S a) + end + + (* atoms of type nat : we add a positivity condition (if not already there) *) + | H : context [ Z_of_nat ?a ] |- _ => + match goal with + | H' : 0 <= Z_of_nat a |- _ => hide_Z_of_nat a + | H' : 0 <= Z_of_nat' a |- _ => fail + | _ => let H:= fresh "H" in + assert (H:=Zle_0_nat a); hide_Z_of_nat a + end + | |- context [ Z_of_nat ?a ] => + match goal with + | H' : 0 <= Z_of_nat a |- _ => hide_Z_of_nat a + | H' : 0 <= Z_of_nat' a |- _ => fail + | _ => let H:= fresh "H" in + assert (H:=Zle_0_nat a); hide_Z_of_nat a + end + end. + +Ltac zify_nat := repeat zify_nat_rel; repeat zify_nat_op; unfold Z_of_nat' in *. + + + + +(* III) conversion from positive to Z *) + +Definition Zpos' := Zpos. +Definition Zneg' := Zneg. + +Ltac hide_Zpos t := + let z := fresh "z" in set (z:=Zpos t) in *; + change Zpos with Zpos' in z; + unfold z in *; clear z. + +Ltac zify_positive_rel := + match goal with + (* I: equalities *) + | H : (@eq positive ?a ?b) |- _ => generalize (Zpos_eq _ _ H); clear H; intro H + | |- (@eq positive ?a ?b) => apply (Zpos_eq_rev a b) + | H : context [ @eq positive ?a ?b ] |- _ => rewrite (Zpos_eq_iff a b) in H + | |- context [ @eq positive ?a ?b ] => rewrite (Zpos_eq_iff a b) + (* II: less than *) + | H : context [ (?a<?b)%positive ] |- _ => change (a<b)%positive with (Zpos a<Zpos b) in H + | |- context [ (?a<?b)%positive ] => change (a<b)%positive with (Zpos a<Zpos b) + (* III: less or equal *) + | H : context [ (?a<=?b)%positive ] |- _ => change (a<=b)%positive with (Zpos a<=Zpos b) in H + | |- context [ (?a<=?b)%positive ] => change (a<=b)%positive with (Zpos a<=Zpos b) + (* IV: greater than *) + | H : context [ (?a>?b)%positive ] |- _ => change (a>b)%positive with (Zpos a>Zpos b) in H + | |- context [ (?a>?b)%positive ] => change (a>b)%positive with (Zpos a>Zpos b) + (* V: greater or equal *) + | H : context [ (?a>=?b)%positive ] |- _ => change (a>=b)%positive with (Zpos a>=Zpos b) in H + | |- context [ (?a>=?b)%positive ] => change (a>=b)%positive with (Zpos a>=Zpos b) + end. + +Ltac zify_positive_op := + match goal with + (* Zneg -> -Zpos (except for numbers) *) + | H : context [ Zneg ?a ] |- _ => + let isp := isPcst a in + match isp with + | true => change (Zneg a) with (Zneg' a) in H + | _ => change (Zneg a) with (- Zpos a) in H + end + | |- context [ Zneg ?a ] => + let isp := isPcst a in + match isp with + | true => change (Zneg a) with (Zneg' a) + | _ => change (Zneg a) with (- Zpos a) + end + + (* misc type conversions: nat to positive *) + | H : context [ Zpos (P_of_succ_nat ?a) ] |- _ => rewrite (Zpos_P_of_succ_nat a) in H + | |- context [ Zpos (P_of_succ_nat ?a) ] => rewrite (Zpos_P_of_succ_nat a) + + (* Pplus -> Zplus *) + | H : context [ Zpos (Pplus ?a ?b) ] |- _ => change (Zpos (Pplus a b)) with (Zplus (Zpos a) (Zpos b)) in H + | |- context [ Zpos (Pplus ?a ?b) ] => change (Zpos (Pplus a b)) with (Zplus (Zpos a) (Zpos b)) + + (* Pmin -> Zmin *) + | H : context [ Zpos (Pmin ?a ?b) ] |- _ => rewrite (Zpos_min a b) in H + | |- context [ Zpos (Pmin ?a ?b) ] => rewrite (Zpos_min a b) + + (* Pmax -> Zmax *) + | H : context [ Zpos (Pmax ?a ?b) ] |- _ => rewrite (Zpos_max a b) in H + | |- context [ Zpos (Pmax ?a ?b) ] => rewrite (Zpos_max a b) + + (* Pminus -> Zmax 1 (Zminus ... ...) *) + | H : context [ Zpos (Pminus ?a ?b) ] |- _ => rewrite (Zpos_minus a b) in H + | |- context [ Zpos (Pminus ?a ?b) ] => rewrite (Zpos_minus a b) + + (* Psucc -> Zsucc *) + | H : context [ Zpos (Psucc ?a) ] |- _ => rewrite (Zpos_succ_morphism a) in H + | |- context [ Zpos (Psucc ?a) ] => rewrite (Zpos_succ_morphism a) + + (* Ppred -> Pminus ... -1 -> Zmax 1 (Zminus ... - 1) *) + | H : context [ Zpos (Ppred ?a) ] |- _ => rewrite (Ppred_minus a) in H + | |- context [ Zpos (Ppred ?a) ] => rewrite (Ppred_minus a) + + (* Pmult -> Zmult and a positivity hypothesis *) + | H : context [ Zpos (Pmult ?a ?b) ] |- _ => + let H:= fresh "H" in + assert (H:=Zgt_pos_0 (Pmult a b)); rewrite (Zpos_mult_morphism a b) in * + | |- context [ Zpos (Pmult ?a ?b) ] => + let H:= fresh "H" in + assert (H:=Zgt_pos_0 (Pmult a b)); rewrite (Zpos_mult_morphism a b) in * + + (* xO *) + | H : context [ Zpos (xO ?a) ] |- _ => + let isp := isPcst a in + match isp with + | true => change (Zpos (xO a)) with (Zpos' (xO a)) in H + | _ => rewrite (Zpos_xO a) in H + end + | |- context [ Zpos (xO ?a) ] => + let isp := isPcst a in + match isp with + | true => change (Zpos (xO a)) with (Zpos' (xO a)) + | _ => rewrite (Zpos_xO a) + end + (* xI *) + | H : context [ Zpos (xI ?a) ] |- _ => + let isp := isPcst a in + match isp with + | true => change (Zpos (xI a)) with (Zpos' (xI a)) in H + | _ => rewrite (Zpos_xI a) in H + end + | |- context [ Zpos (xI ?a) ] => + let isp := isPcst a in + match isp with + | true => change (Zpos (xI a)) with (Zpos' (xI a)) + | _ => rewrite (Zpos_xI a) + end + + (* xI : nothing to do, just prevent adding a useless positivity condition *) + | H : context [ Zpos xH ] |- _ => hide_Zpos xH + | |- context [ Zpos xH ] => hide_Zpos xH + + (* atoms of type positive : we add a positivity condition (if not already there) *) + | H : context [ Zpos ?a ] |- _ => + match goal with + | H' : Zpos a > 0 |- _ => hide_Zpos a + | H' : Zpos' a > 0 |- _ => fail + | _ => let H:= fresh "H" in assert (H:=Zgt_pos_0 a); hide_Zpos a + end + | |- context [ Zpos ?a ] => + match goal with + | H' : Zpos a > 0 |- _ => hide_Zpos a + | H' : Zpos' a > 0 |- _ => fail + | _ => let H:= fresh "H" in assert (H:=Zgt_pos_0 a); hide_Zpos a + end + end. + +Ltac zify_positive := + repeat zify_positive_rel; repeat zify_positive_op; unfold Zpos',Zneg' in *. + + + + + +(* IV) conversion from N to Z *) + +Definition Z_of_N' := Z_of_N. + +Ltac hide_Z_of_N t := + let z := fresh "z" in set (z:=Z_of_N t) in *; + change Z_of_N with Z_of_N' in z; + unfold z in *; clear z. + +Ltac zify_N_rel := + match goal with + (* I: equalities *) + | H : (@eq N ?a ?b) |- _ => generalize (Z_of_N_eq _ _ H); clear H; intro H + | |- (@eq N ?a ?b) => apply (Z_of_N_eq_rev a b) + | H : context [ @eq N ?a ?b ] |- _ => rewrite (Z_of_N_eq_iff a b) in H + | |- context [ @eq N ?a ?b ] => rewrite (Z_of_N_eq_iff a b) + (* II: less than *) + | H : (?a<?b)%N |- _ => generalize (Z_of_N_lt _ _ H); clear H; intro H + | |- (?a<?b)%N => apply (Z_of_N_lt_rev a b) + | H : context [ (?a<?b)%N ] |- _ => rewrite (Z_of_N_lt_iff a b) in H + | |- context [ (?a<?b)%N ] => rewrite (Z_of_N_lt_iff a b) + (* III: less or equal *) + | H : (?a<=?b)%N |- _ => generalize (Z_of_N_le _ _ H); clear H; intro H + | |- (?a<=?b)%N => apply (Z_of_N_le_rev a b) + | H : context [ (?a<=?b)%N ] |- _ => rewrite (Z_of_N_le_iff a b) in H + | |- context [ (?a<=?b)%N ] => rewrite (Z_of_N_le_iff a b) + (* IV: greater than *) + | H : (?a>?b)%N |- _ => generalize (Z_of_N_gt _ _ H); clear H; intro H + | |- (?a>?b)%N => apply (Z_of_N_gt_rev a b) + | H : context [ (?a>?b)%N ] |- _ => rewrite (Z_of_N_gt_iff a b) in H + | |- context [ (?a>?b)%N ] => rewrite (Z_of_N_gt_iff a b) + (* V: greater or equal *) + | H : (?a>=?b)%N |- _ => generalize (Z_of_N_ge _ _ H); clear H; intro H + | |- (?a>=?b)%N => apply (Z_of_N_ge_rev a b) + | H : context [ (?a>=?b)%N ] |- _ => rewrite (Z_of_N_ge_iff a b) in H + | |- context [ (?a>=?b)%N ] => rewrite (Z_of_N_ge_iff a b) + end. + +Ltac zify_N_op := + match goal with + (* misc type conversions: nat to positive *) + | H : context [ Z_of_N (N_of_nat ?a) ] |- _ => rewrite (Z_of_N_of_nat a) in H + | |- context [ Z_of_N (N_of_nat ?a) ] => rewrite (Z_of_N_of_nat a) + | H : context [ Z_of_N (Zabs_N ?a) ] |- _ => rewrite (Z_of_N_abs a) in H + | |- context [ Z_of_N (Zabs_N ?a) ] => rewrite (Z_of_N_abs a) + | H : context [ Z_of_N (Npos ?a) ] |- _ => rewrite (Z_of_N_pos a) in H + | |- context [ Z_of_N (Npos ?a) ] => rewrite (Z_of_N_pos a) + | H : context [ Z_of_N N0 ] |- _ => change (Z_of_N N0) with Z0 in H + | |- context [ Z_of_N N0 ] => change (Z_of_N N0) with Z0 + + (* Nplus -> Zplus *) + | H : context [ Z_of_N (Nplus ?a ?b) ] |- _ => rewrite (Z_of_N_plus a b) in H + | |- context [ Z_of_N (Nplus ?a ?b) ] => rewrite (Z_of_N_plus a b) + + (* Nmin -> Zmin *) + | H : context [ Z_of_N (Nmin ?a ?b) ] |- _ => rewrite (Z_of_N_min a b) in H + | |- context [ Z_of_N (Nmin ?a ?b) ] => rewrite (Z_of_N_min a b) + + (* Nmax -> Zmax *) + | H : context [ Z_of_N (Nmax ?a ?b) ] |- _ => rewrite (Z_of_N_max a b) in H + | |- context [ Z_of_N (Nmax ?a ?b) ] => rewrite (Z_of_N_max a b) + + (* Nminus -> Zmax 0 (Zminus ... ...) *) + | H : context [ Z_of_N (Nminus ?a ?b) ] |- _ => rewrite (Z_of_N_minus a b) in H + | |- context [ Z_of_N (Nminus ?a ?b) ] => rewrite (Z_of_N_minus a b) + + (* Nsucc -> Zsucc *) + | H : context [ Z_of_N (Nsucc ?a) ] |- _ => rewrite (Z_of_N_succ a) in H + | |- context [ Z_of_N (Nsucc ?a) ] => rewrite (Z_of_N_succ a) + + (* Nmult -> Zmult and a positivity hypothesis *) + | H : context [ Z_of_N (Nmult ?a ?b) ] |- _ => + let H:= fresh "H" in + assert (H:=Z_of_N_le_0 (Nmult a b)); rewrite (Z_of_N_mult a b) in * + | |- context [ Z_of_N (Nmult ?a ?b) ] => + let H:= fresh "H" in + assert (H:=Z_of_N_le_0 (Nmult a b)); rewrite (Z_of_N_mult a b) in * + + (* atoms of type N : we add a positivity condition (if not already there) *) + | H : context [ Z_of_N ?a ] |- _ => + match goal with + | H' : 0 <= Z_of_N a |- _ => hide_Z_of_N a + | H' : 0 <= Z_of_N' a |- _ => fail + | _ => let H:= fresh "H" in assert (H:=Z_of_N_le_0 a); hide_Z_of_N a + end + | |- context [ Z_of_N ?a ] => + match goal with + | H' : 0 <= Z_of_N a |- _ => hide_Z_of_N a + | H' : 0 <= Z_of_N' a |- _ => fail + | _ => let H:= fresh "H" in assert (H:=Z_of_N_le_0 a); hide_Z_of_N a + end + end. + +Ltac zify_N := repeat zify_N_rel; repeat zify_N_op; unfold Z_of_N' in *. + + + +(** The complete Z-ification tactic *) + +Ltac zify := + repeat progress (zify_nat; zify_positive; zify_N); zify_op. + |