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Diffstat (limited to 'ci/test_wholefile.v')
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diff --git a/ci/test_wholefile.v b/ci/test_wholefile.v new file mode 100644 index 00000000..9deee01d --- /dev/null +++ b/ci/test_wholefile.v @@ -0,0 +1,145 @@ +(* taken from https://coq.inria.fr/distrib/8.2/contribs/QArithSternBrocot.sqrt2.html *) +(* Note: this file contains no "Proof" command (invariant to preserve) + in order to exercise 070_coq-test-regression-wholefile-no-proof. *) + +Require Export ArithRing. +Require Export Compare_dec. +Require Export Wf_nat. +Require Export Arith. +Require Export Omega. + +Theorem minus_minus : forall a b c : nat, a - b - c = a - (b + c). +intros a; elim a; auto. +intros n' Hrec b; case b; auto. +Qed. + +Remark expand_mult2 : forall x : nat, 2 * x = x + x. +intros x; ring. +Qed. + +Theorem lt_neq : forall x y : nat, x < y -> x <> y. +unfold not in |- *; intros x y H H1; elim (lt_irrefl x); + pattern x at 2 in |- *; rewrite H1; auto. +Qed. +Hint Resolve lt_neq. + +Theorem monotonic_inverse : + forall f : nat -> nat, + (forall x y : nat, x < y -> f x < f y) -> + forall x y : nat, f x < f y -> x < y. +intros f Hmon x y Hlt; case (le_gt_dec y x); auto. +intros Hle; elim (le_lt_or_eq _ _ Hle). +intros Hlt'; elim (lt_asym _ _ Hlt); apply Hmon; auto. +intros Heq; elim (lt_neq _ _ Hlt); rewrite Heq; auto. +Qed. + +Theorem mult_lt : forall a b c : nat, c <> 0 -> a < b -> a * c < b * c. +intros a b c; elim c. +intros H; elim H; auto. +intros c'; case c'. +intros; omega. +intros c'' Hrec Hneq Hlt; + repeat rewrite <- (fun x : nat => mult_n_Sm x (S c'')). +auto with *. +Qed. + +Remark add_sub_square_identity : + forall a b : nat, + (b + a - b) * (b + a - b) = (b + a) * (b + a) + b * b - 2 * ((b + a) * b). +intros a b; rewrite minus_plus. +repeat rewrite mult_plus_distr_r || rewrite <- (mult_comm (b + a)). +replace (b * b + a * b + (b * a + a * a) + b * b) with + (b * b + a * b + (b * b + a * b + a * a)); try (ring; fail). +rewrite expand_mult2; repeat rewrite minus_plus; auto with *. +Qed. + +Theorem sub_square_identity : + forall a b : nat, b <= a -> (a - b) * (a - b) = a * a + b * b - 2 * (a * b). +intros a b H; rewrite (le_plus_minus b a H); apply add_sub_square_identity. +Qed. + +Theorem square_monotonic : forall x y : nat, x < y -> x * x < y * y. +intros x; case x. +intros y; case y; simpl in |- *; auto with *. +intros x' y Hlt; apply lt_trans with (S x' * y). +rewrite (mult_comm (S x') y); apply mult_lt; auto. +apply mult_lt; omega. +Qed. + +Theorem root_monotonic : forall x y : nat, x * x < y * y -> x < y. +exact (monotonic_inverse (fun x : nat => x * x) square_monotonic). +Qed. + +Remark square_recompose : forall x y : nat, x * y * (x * y) = x * x * (y * y). +intros; ring. +Qed. + +Remark mult2_recompose : forall x y : nat, x * (2 * y) = x * 2 * y. +intros; ring. +Qed. +Section sqrt2_decrease. +Variables (p q : nat) (pos_q : 0 < q) (hyp_sqrt : p * p = 2 * (q * q)). + +Theorem sqrt_q_non_zero : 0 <> q * q. +generalize pos_q; case q. +intros H; elim (lt_n_O 0); auto. +intros n H. +simpl in |- *; discriminate. +Qed. +Hint Resolve sqrt_q_non_zero. + +Ltac solve_comparison := + apply root_monotonic; repeat rewrite square_recompose; rewrite hyp_sqrt; + rewrite mult2_recompose; apply mult_lt; auto with arith. + +Theorem comparison1 : q < p. +replace q with (1 * q); try ring. +replace p with (1 * p); try ring. +solve_comparison. +Qed. + +Theorem comparison2 : 2 * p < 3 * q. +solve_comparison. +Qed. + +Theorem comparison3 : 4 * q < 3 * p. +solve_comparison. +Qed. +Hint Resolve comparison1 comparison2 comparison3: arith. + +Theorem comparison4 : 3 * q - 2 * p < q. +apply plus_lt_reg_l with (2 * p). +rewrite <- le_plus_minus; try (simple apply lt_le_weak; auto with arith). +replace (3 * q) with (2 * q + q); try ring. +apply plus_lt_le_compat; auto. +repeat rewrite (mult_comm 2); apply mult_lt; auto with arith. +Qed. + +Remark mult_minus_distr_l : forall a b c : nat, a * (b - c) = a * b - a * c. +intros a b c; repeat rewrite (mult_comm a); apply mult_minus_distr_r. +Qed. + +Remark minus_eq_decompose : + forall a b c d : nat, a = b -> c = d -> a - c = b - d. +intros a b c d H H0; rewrite H; rewrite H0; auto. +Qed. + +Theorem new_equality : + (3 * p - 4 * q) * (3 * p - 4 * q) = 2 * ((3 * q - 2 * p) * (3 * q - 2 * p)). +repeat rewrite sub_square_identity; auto with arith. +repeat rewrite square_recompose; rewrite mult_minus_distr_l. +apply minus_eq_decompose; try rewrite hyp_sqrt; ring. +Qed. +End sqrt2_decrease. +Hint Resolve lt_le_weak comparison2: sqrt. + +Theorem sqrt2_not_rational : + forall p q : nat, q <> 0 -> p * p = 2 * (q * q) -> False. +intros p q; generalize p; clear p; elim q using (well_founded_ind lt_wf). +clear q; intros q Hrec p Hneq; generalize (neq_O_lt _ (sym_not_equal Hneq)); + intros Hlt_O_q Heq. +apply (Hrec (3 * q - 2 * p) (comparison4 _ _ Hlt_O_q Heq) (3 * p - 4 * q)). +apply sym_not_equal; apply lt_neq; apply plus_lt_reg_l with (2 * p); + rewrite <- plus_n_O; rewrite <- le_plus_minus; auto with *. +apply new_equality; auto. +Qed. |
