diff options
Diffstat (limited to 'doc/sphinx/proof-engine')
| -rw-r--r-- | doc/sphinx/proof-engine/ltac.rst | 8 | ||||
| -rw-r--r-- | doc/sphinx/proof-engine/ssreflect-proof-language.rst | 192 | ||||
| -rw-r--r-- | doc/sphinx/proof-engine/tactics.rst | 137 |
3 files changed, 179 insertions, 158 deletions
diff --git a/doc/sphinx/proof-engine/ltac.rst b/doc/sphinx/proof-engine/ltac.rst index 442077616f..4f486a777d 100644 --- a/doc/sphinx/proof-engine/ltac.rst +++ b/doc/sphinx/proof-engine/ltac.rst @@ -859,6 +859,10 @@ We can carry out pattern matching on terms with: Goal True. f (3+4). + .. coqtop:: none + + Abort. + .. _ltac-match-goal: Pattern matching on goals @@ -1026,6 +1030,10 @@ Counting the goals all:pr_numgoals. + .. coqtop:: none + + Abort. + Testing boolean expressions ~~~~~~~~~~~~~~~~~~~~~~~~~~~ diff --git a/doc/sphinx/proof-engine/ssreflect-proof-language.rst b/doc/sphinx/proof-engine/ssreflect-proof-language.rst index 483dbd311d..ec97377128 100644 --- a/doc/sphinx/proof-engine/ssreflect-proof-language.rst +++ b/doc/sphinx/proof-engine/ssreflect-proof-language.rst @@ -233,7 +233,7 @@ construct differs from the latter in that .. coqtop:: reset all - Definition f u := let (m, n) := u in m + n. + Fail Definition f u := let (m, n) := u in m + n. The ``let:`` construct is just (more legible) notation for the primitive @@ -413,7 +413,7 @@ each point of use, e.g., the above definition can be written: Variable all : (T -> bool) -> list T -> bool. - .. coqtop:: all undo + .. coqtop:: all Prenex Implicits null. Definition all_null (s : list T) := all null s. @@ -436,7 +436,7 @@ The syntax of the new declaration is a ``Set Printing All`` command). All |SSR| library files thus start with the incantation - .. coqtop:: all undo + .. coqdoc:: Set Implicit Arguments. Unset Strict Implicit. @@ -505,7 +505,7 @@ Definitions |SSR| pose tactic supports *open syntax*: the body of the definition does not need surrounding parentheses. For instance: -.. coqtop:: in +.. coqdoc:: pose t := x + y. @@ -534,7 +534,7 @@ The |SSR| pose tactic also supports (co)fixpoints, by providing the local counterpart of the ``Fixpoint f := …`` and ``CoFixpoint f := …`` constructs. For instance, the following tactic: -.. coqtop:: in +.. coqdoc:: pose fix f (x y : nat) {struct x} : nat := if x is S p then S (f p y) else 0. @@ -544,7 +544,7 @@ on natural numbers. Similarly, local cofixpoints can be defined by a tactic of the form: -.. coqtop:: in +.. coqdoc:: pose cofix f (arg : T) := … . @@ -553,26 +553,26 @@ offers a smooth way of defining local abstractions. The type of “holes” is guessed by type inference, and the holes are abstracted. For instance the tactic: -.. coqtop:: in +.. coqdoc:: pose f := _ + 1. is shorthand for: -.. coqtop:: in +.. coqdoc:: pose f n := n + 1. When the local definition of a function involves both arguments and holes, hole abstractions appear first. For instance, the tactic: -.. coqtop:: in +.. coqdoc:: pose f x := x + _. is shorthand for: -.. coqtop:: in +.. coqdoc:: pose f n x := x + n. @@ -580,13 +580,13 @@ The interaction of the pose tactic with the interpretation of implicit arguments results in a powerful and concise syntax for local definitions involving dependent types. For instance, the tactic: -.. coqtop:: in +.. coqdoc:: pose f x y := (x, y). adds to the context the local definition: -.. coqtop:: in +.. coqdoc:: pose f (Tx Ty : Type) (x : Tx) (y : Ty) := (x, y). @@ -766,7 +766,7 @@ Moreover: .. coqtop:: all Lemma test : forall x : nat, x + 1 = 0. - set t := _ + 1. + Fail set t := _ + 1. + Typeclass inference should fill in any residual hole, but matching should never assign a value to a global existential variable. @@ -889,7 +889,7 @@ only one occurrence of the selected term. .. coqtop:: all Lemma test x y z : (x + y) + (z + z) = z + z. - set a := {2}(_ + _). + Fail set a := {2}(_ + _). .. _basic_localization_ssr: @@ -1079,7 +1079,7 @@ constants to the goal. Because they are tacticals, ``:`` and ``=>`` can be combined, as in -.. coqtop:: in +.. coqdoc:: move: m le_n_m => p le_n_p. @@ -1139,7 +1139,7 @@ Basic tactics like apply and elim can also be used without the ’:’ tactical: for example we can directly start a proof of ``subnK`` by induction on the top variable ``m`` with -.. coqtop:: in +.. coqdoc:: elim=> [|m IHm] n le_n. @@ -1150,7 +1150,7 @@ explained in terms of the goal stack:: is basically equivalent to -.. coqtop:: in +.. coqdoc:: move: a H1 H2; tactic => a H1 H2. @@ -1163,13 +1163,13 @@ temporary abbreviation to hide the statement of the goal from The general form of the in tactical can be used directly with the ``move``, ``case`` and ``elim`` tactics, so that one can write -.. coqtop:: in +.. coqdoc:: elim: n => [|n IHn] in m le_n_m *. instead of -.. coqtop:: in +.. coqdoc:: elim: n m le_n_m => [|n IHn] m le_n_m. @@ -1398,7 +1398,7 @@ Switches affect the discharging of a :token:`d_item` as follows: For example, the tactic: -.. coqtop:: in +.. coqdoc:: move: n {2}n (refl_equal n). @@ -1409,7 +1409,7 @@ For example, the tactic: Therefore this tactic changes any goal ``G`` into -.. coqtop:: +.. coqdoc:: forall n n0 : nat, n = n0 -> G. @@ -1843,7 +1843,7 @@ Generation of equations The generation of named equations option stores the definition of a new constant as an equation. The tactic: -.. coqtop:: in +.. coqdoc:: move En: (size l) => n. @@ -1851,7 +1851,7 @@ where ``l`` is a list, replaces ``size l`` by ``n`` in the goal and adds the fact ``En : size l = n`` to the context. This is quite different from: -.. coqtop:: in +.. coqdoc:: pose n := (size l). @@ -1936,7 +1936,7 @@ be substituted. inferred looking at the type of the top assumption. This allows for the compact syntax: - .. coqtop:: in + .. coqdoc:: case: {2}_ / eqP. @@ -2112,7 +2112,7 @@ In the script provided as example in section :ref:`indentation_ssr`, the paragraph corresponding to each sub-case ends with a tactic line prefixed with a ``by``, like in: -.. coqtop:: in +.. coqdoc:: by apply/eqP; rewrite -dvdn1. @@ -2147,13 +2147,13 @@ A natural and common way of closing a goal is to apply a lemma which is the exact one needed for the goal to be solved. The defective form of the tactic: -.. coqtop:: in +.. coqdoc:: exact. is equivalent to: -.. coqtop:: in +.. coqdoc:: do [done | by move=> top; apply top]. @@ -2161,13 +2161,13 @@ where ``top`` is a fresh name assigned to the top assumption of the goal. This applied form is supported by the ``:`` discharge tactical, and the tactic: -.. coqtop:: in +.. coqdoc:: exact: MyLemma. is equivalent to: -.. coqtop:: in +.. coqdoc:: by apply: MyLemma. @@ -2179,19 +2179,19 @@ is equivalent to: follows the ``by`` keyword is considered to be a parenthesized block applied to the current goal. Hence for example if the tactic: - .. coqtop:: in + .. coqdoc:: by rewrite my_lemma1. succeeds, then the tactic: - .. coqtop:: in + .. coqdoc:: by rewrite my_lemma1; apply my_lemma2. usually fails since it is equivalent to: - .. coqtop:: in + .. coqdoc:: by (rewrite my_lemma1; apply my_lemma2). @@ -2247,7 +2247,7 @@ Finally, the tactics ``last`` and ``first`` combine with the branching syntax of Ltac: if the tactic generates n subgoals on a given goal, then the tactic -.. coqtop:: in +.. coqdoc:: tactic ; last k [ tactic1 |…| tacticm ] || tacticn. @@ -2262,7 +2262,6 @@ to the others. .. coqtop:: reset - Abort. From Coq Require Import ssreflect. Set Implicit Arguments. Unset Strict Implicit. @@ -2296,13 +2295,13 @@ Iteration A tactic of the form: -.. coqtop:: in +.. coqdoc:: do [ tactic 1 | … | tactic n ]. is equivalent to the standard Ltac expression: -.. coqtop:: in +.. coqdoc:: first [ tactic 1 | … | tactic n ]. @@ -2327,14 +2326,14 @@ Their meaning is: For instance, the tactic: -.. coqtop:: in +.. coqdoc:: tactic; do 1? rewrite mult_comm. rewrites at most one time the lemma ``mult_comm`` in all the subgoals generated by tactic , whereas the tactic: -.. coqtop:: in +.. coqdoc:: tactic; do 2! rewrite mult_comm. @@ -2518,7 +2517,7 @@ tactics of the form: which behave like: -.. coqtop:: in +.. coqdoc:: have: term ; first by tactic. move=> clear_switch i_item. @@ -2531,7 +2530,7 @@ to introduce the new assumption itself. The ``by`` feature is especially convenient when the proof script of the statement is very short, basically when it fits in one line like in: -.. coqtop:: in +.. coqdoc:: have H23 : 3 + 2 = 2 + 3 by rewrite addnC. @@ -2559,7 +2558,7 @@ the further use of the intermediate step. For instance, Thanks to the deferred execution of clears, the following idiom is also supported (assuming x occurs in the goal only): -.. coqtop:: in +.. coqdoc:: have {x} -> : x = y. @@ -2635,7 +2634,7 @@ Since the :token:`i_pattern` can be omitted, to avoid ambiguity, bound variables can be surrounded with parentheses even if no type is specified: -.. coqtop:: in +.. coqdoc:: have (x) : 2 * x = x + x by omega. @@ -2816,7 +2815,7 @@ The + but the optional clear item is still performed in the *second* branch. This means that the tactic: - .. coqtop:: in + .. coqdoc:: suff {H} H : forall x : nat, x >= 0. @@ -2888,7 +2887,7 @@ name of the local definition with the ``@`` character. In the second subgoal, the tactic: -.. coqtop:: in +.. coqdoc:: move=> clear_switch i_item. @@ -2995,10 +2994,13 @@ illustrated in the following example. the pattern ``id (addx x)``, that would produce the following first subgoal - .. coqtop:: none + .. coqtop:: none reset + + From Coq Require Import ssreflect Omega. + Set Implicit Arguments. + Unset Strict Implicit. + Unset Printing Implicit Defensive. - Abort All. - From Coq Require Import Omega. Section Test. Variable x : nat. Definition addx z := z + x. @@ -3153,7 +3155,7 @@ An :token:`r_item` can be: Definition f := fun x y => x + y. Lemma test x y : x + y = f y x. - rewrite -[f y]/(y + _). + Fail rewrite -[f y]/(y + _). but the following script succeeds @@ -3192,7 +3194,7 @@ tactics. In a rewrite tactic of the form: -.. coqtop:: in +.. coqdoc:: rewrite occ_switch [term1]term2. @@ -3235,7 +3237,7 @@ Performing rewrite and simplification operations in a single tactic enhances significantly the concision of scripts. For instance the tactic: -.. coqtop:: in +.. coqdoc:: rewrite /my_def {2}[f _]/= my_eq //=. @@ -3316,7 +3318,7 @@ the equality. .. coqtop:: all Lemma test (H : forall t u, t + u * 0 = t) x y : x + y * 4 + 2 * 0 = x + 2 * 0. - rewrite [x + _]H. + Fail rewrite [x + _]H. Indeed the left hand side of ``H`` does not match the redex identified by the pattern ``x + y * 4``. @@ -3498,7 +3500,7 @@ reasoning purposes. The library also provides one lemma per such operation, stating that both versions return the same values when applied to the same arguments: -.. coqtop:: in +.. coqdoc:: Lemma addE : add =2 addn. Lemma doubleE : double =1 doublen. @@ -3514,7 +3516,7 @@ hand side. In order to reason conveniently on expressions involving the efficient operations, we gather all these rules in the definition ``trecE``: -.. coqtop:: in +.. coqdoc:: Definition trecE := (addE, (doubleE, oddE), (mulE, add_mulE, (expE, mul_expE))). @@ -3572,14 +3574,14 @@ cases: + |SSR| never accepts to rewrite indeterminate patterns like: - .. coqtop:: in + .. coqdoc:: Lemma foo (x : unit) : x = tt. |SSR| will however accept the ηζ expansion of this rule: - .. coqtop:: in + .. coqdoc:: Lemma fubar (x : unit) : (let u := x in u) = tt. @@ -3617,7 +3619,7 @@ cases: .. coqtop:: all - rewrite H. + Fail rewrite H. Rewriting with ``H`` first requires unfolding the occurrences of ``f`` @@ -3729,7 +3731,7 @@ copy of any term t. However this copy is (on purpose) *not convertible* to t in the |Coq| system [#8]_. The job is done by the following construction: -.. coqtop:: in +.. coqdoc:: Lemma master_key : unit. Proof. exact tt. Qed. Definition locked A := let: tt := master_key in fun x : A => x. @@ -3793,14 +3795,14 @@ some functions by the partial evaluation switch ``/=``, unless this allowed the evaluation of a condition. This is possible thanks to another mechanism of term tagging, resting on the following *Notation*: -.. coqtop:: in +.. coqdoc:: Notation "'nosimpl' t" := (let: tt := tt in t). The term ``(nosimpl t)`` simplifies to ``t`` *except* in a definition. More precisely, given: -.. coqtop:: in +.. coqdoc:: Definition foo := (nosimpl bar). @@ -3816,7 +3818,7 @@ Note that ``nosimpl bar`` is simply notation for a term that reduces to The ``nosimpl`` trick only works if no reduction is apparent in ``t``; in particular, the declaration: - .. coqtop:: in + .. coqdoc:: Definition foo x := nosimpl (bar x). @@ -3824,14 +3826,14 @@ Note that ``nosimpl bar`` is simply notation for a term that reduces to function, and to use the following definition, which blocks the reduction as expected: - .. coqtop:: in + .. coqdoc:: Definition foo x := nosimpl bar x. A standard example making this technique shine is the case of arithmetic operations. We define for instance: -.. coqtop:: in +.. coqdoc:: Definition addn := nosimpl plus. @@ -3851,7 +3853,7 @@ Congruence Because of the way matching interferes with parameters of type families, the tactic: -.. coqtop:: in +.. coqdoc:: apply: my_congr_property. @@ -4047,7 +4049,7 @@ For a quick glance at what can be expressed with the last :token:`r_pattern` consider the goal ``a = b`` and the tactic -.. coqtop:: in +.. coqdoc:: rewrite [in X in _ = X]rule. @@ -4148,14 +4150,14 @@ patterns over simple terms, but to interpret a pattern with double parentheses as a simple term. For example, the following tactic would capture any occurrence of the term ``a in A``. -.. coqtop:: in +.. coqdoc:: set t := ((a in A)). Contextual patterns can also be used as arguments of the ``:`` tactical. For example: -.. coqtop:: in +.. coqdoc:: elim: n (n in _ = n) (refl_equal n). @@ -4246,7 +4248,7 @@ context shortcuts. The following example is taken from ``ssreflect.v`` where the ``LHS`` and ``RHS`` shortcuts are defined. -.. coqtop:: in +.. coqdoc:: Notation RHS := (X in _ = X)%pattern. Notation LHS := (X in X = _)%pattern. @@ -4254,7 +4256,7 @@ The following example is taken from ``ssreflect.v`` where the Shortcuts defined this way can be freely used in place of the trailing ``ident in term`` part of any contextual pattern. Some examples follow: -.. coqtop:: in +.. coqdoc:: set rhs := RHS. rewrite [in RHS]rule. @@ -4287,13 +4289,13 @@ The view syntax combined with the ``elim`` tactic specifies an elimination scheme to be used instead of the default, generated, one. Hence the |SSR| tactic: -.. coqtop:: in +.. coqdoc:: elim/V. is a synonym for: -.. coqtop:: in +.. coqdoc:: intro top; elim top using V; clear top. @@ -4303,13 +4305,13 @@ Since an elimination view supports the two bookkeeping tacticals of discharge and introduction (see section :ref:`basic_tactics_ssr`), the |SSR| tactic: -.. coqtop:: in +.. coqdoc:: elim/V: x => y. is a synonym for: -.. coqtop:: in +.. coqdoc:: elim x using V; clear x; intro y. @@ -4367,13 +4369,13 @@ command) can be combined with the type family switches described in section :ref:`type_families_ssr`. Consider an eliminator ``foo_ind`` of type: -.. coqtop:: in +.. coqdoc:: foo_ind : forall …, forall x : T, P p1 … pm. and consider the tactic: -.. coqtop:: in +.. coqdoc:: elim/foo_ind: e1 … / en. @@ -4424,7 +4426,7 @@ Here is an example of a regular, but nontrivial, eliminator. The following tactics are all valid and perform the same elimination on this goal. - .. coqtop:: in + .. coqdoc:: elim/plus_ind: z / (plus _ z). elim/plus_ind: {z}(plus _ z). @@ -4473,7 +4475,7 @@ Here is an example of a regular, but nontrivial, eliminator. .. coqtop:: all - elim/plus_ind: y / _. + Fail elim/plus_ind: y / _. triggers an error: in the conclusion of the ``plus_ind`` eliminator, the first argument of the predicate @@ -4494,7 +4496,7 @@ Here is an example of a truncated eliminator: Unset Printing Implicit Defensive. Section Test. - .. coqtop:: in + .. coqdoc:: Lemma test p n (n_gt0 : 0 < n) (pr_p : prime p) : p %| \prod_(i <- prime_decomp n | i \in prime_decomp n) i.1 ^ i.2 -> @@ -4505,7 +4507,7 @@ Here is an example of a truncated eliminator: where the type of the ``big_prop`` eliminator is - .. coqtop:: in + .. coqdoc:: big_prop: forall (R : Type) (Pb : R -> Type) (idx : R) (op1 : R -> R -> R), Pb idx -> @@ -4518,7 +4520,7 @@ Here is an example of a truncated eliminator: inferred one is used instead: ``big[_/_]_(i <- _ | _ i) _ i``, and after the introductions, the following goals are generated: - .. coqtop:: in + .. coqdoc:: subgoal 1 is: p %| 1 -> exists2 x : nat * nat, x \in prime_decomp n & p = x.1 @@ -4624,7 +4626,7 @@ equation name generation mechanism (see section :ref:`generation_of_equations_ss This view tactic performs: - .. coqtop:: in + .. coqdoc:: move=> HQ; case: {HQ}(Q2P HQ) => [HPa | HPb]. @@ -4661,14 +4663,14 @@ relevant for the current goal. the double implication into the expected simple implication. The last script is in fact equivalent to: - .. coqtop:: in + .. coqdoc:: Lemma test a b : P (a || b) -> True. move/(iffLR (PQequiv _ _)). where: - .. coqtop:: in + .. coqdoc:: Lemma iffLR P Q : (P <-> Q) -> P -> Q. @@ -4810,7 +4812,7 @@ decidable predicate to its boolean version. First, booleans are injected into propositions using the coercion mechanism: -.. coqtop:: in +.. coqdoc:: Coercion is_true (b : bool) := b = true. @@ -4827,7 +4829,7 @@ To get all the benefits of the boolean reflection, it is in fact convenient to introduce the following inductive predicate ``reflect`` to relate propositions and booleans: -.. coqtop:: in +.. coqdoc:: Inductive reflect (P: Prop): bool -> Type := | Reflect_true : P -> reflect P true @@ -4838,7 +4840,7 @@ logically equivalent propositions. For instance, the following lemma: -.. coqtop:: in +.. coqdoc:: Lemma andP: forall b1 b2, reflect (b1 /\ b2) (b1 && b2). @@ -4853,20 +4855,20 @@ to the case analysis of |Coq|’s inductive types. Since the equivalence predicate is defined in |Coq| as: -.. coqtop:: in +.. coqdoc:: Definition iff (A B:Prop) := (A -> B) /\ (B -> A). where ``/\`` is a notation for ``and``: -.. coqtop:: in +.. coqdoc:: Inductive and (A B:Prop) : Prop := conj : A -> B -> and A B. This make case analysis very different according to the way an equivalence property has been defined. -.. coqtop:: in +.. coqdoc:: Lemma andE (b1 b2 : bool) : (b1 /\ b2) <-> (b1 && b2). @@ -4950,13 +4952,13 @@ Specializing assumptions The |SSR| tactic: -.. coqtop:: in +.. coqdoc:: move/(_ term1 … termn). is equivalent to the tactic: -.. coqtop:: in +.. coqdoc:: intro top; generalize (top term1 … termn); clear top. @@ -5013,13 +5015,13 @@ If ``term`` is a double implication, then the view hint will be one of the defined view hints for implication. These hints are by default the ones present in the file ``ssreflect.v``: -.. coqtop:: in +.. coqdoc:: Lemma iffLR : forall P Q, (P <-> Q) -> P -> Q. which transforms a double implication into the left-to-right one, or: -.. coqtop:: in +.. coqdoc:: Lemma iffRL : forall P Q, (P <-> Q) -> Q -> P. @@ -5123,7 +5125,7 @@ equality, while the second term is the one applied to the right hand side. In this context, the identity view can be used when no view has to be applied: -.. coqtop:: in +.. coqdoc:: Lemma idP : reflect b1 b1. @@ -5198,7 +5200,7 @@ in sequence. Both move and apply can be followed by an arbitrary number of ``/term``. The main difference between the following two tactics -.. coqtop:: in +.. coqdoc:: apply/v1/v2/v3. apply/v1; apply/v2; apply/v3. @@ -5210,7 +5212,7 @@ line would apply the view ``v2`` to all the goals generated by ``apply/v1``. Note that the NO-OP intro pattern ``-`` can be used to separate two views, making the two following examples equivalent: -.. coqtop:: in +.. coqdoc:: move=> /v1; move=> /v2. move=> /v1 - /v2. diff --git a/doc/sphinx/proof-engine/tactics.rst b/doc/sphinx/proof-engine/tactics.rst index 081fef07b9..0bcfce2322 100644 --- a/doc/sphinx/proof-engine/tactics.rst +++ b/doc/sphinx/proof-engine/tactics.rst @@ -2493,7 +2493,7 @@ and an explanation of the underlying technique. Let us consider the relation Le over natural numbers and the following variables: - .. coqtop:: all + .. coqtop:: all reset Inductive Le : nat -> nat -> Set := | LeO : forall n:nat, Le 0 n @@ -3406,129 +3406,140 @@ Automation This tactic implements a Prolog-like resolution procedure to solve the current goal. It first tries to solve the goal using the :tacn:`assumption` - tactic, then it reduces the goal to an atomic one using intros and + tactic, then it reduces the goal to an atomic one using :tacn:`intros` and introduces the newly generated hypotheses as hints. Then it looks at the list of tactics associated to the head symbol of the goal and tries to apply one of them (starting from the tactics with lower cost). This process is recursively applied to the generated subgoals. - By default, auto only uses the hypotheses of the current goal and the - hints of the database named core. + By default, :tacn:`auto` only uses the hypotheses of the current goal and + the hints of the database named ``core``. + + .. warning:: + + :tacn:`auto` uses a weaker version of :tacn:`apply` that is closer to + :tacn:`simple apply` so it is expected that sometimes :tacn:`auto` will + fail even if applying manually one of the hints would succeed. + + .. tacv:: auto @num + + Forces the search depth to be :token:`num`. The maximal search depth + is 5 by default. + + .. tacv:: auto with {+ @ident} -.. tacv:: auto @num + Uses the hint databases :n:`{+ @ident}` in addition to the database ``core``. - Forces the search depth to be :token:`num`. The maximal search depth - is 5 by default. + .. note:: + + Use the fake database `nocore` if you want to *not* use the `core` + database. -.. tacv:: auto with {+ @ident} + .. tacv:: auto with * - Uses the hint databases :n:`{+ @ident}` in addition to the database core. + Uses all existing hint databases. Using this variant is highly discouraged + in finished scripts since it is both slower and less robust than the variant + where the required databases are explicitly listed. .. seealso:: :ref:`The Hints Databases for auto and eauto <thehintsdatabasesforautoandeauto>` for the list of pre-defined databases and the way to create or extend a database. -.. tacv:: auto with * + .. tacv:: auto using {+ @ident__i} {? with {+ @ident } } - Uses all existing hint databases. + Uses lemmas :n:`@ident__i` in addition to hints. If :n:`@ident` is an + inductive type, it is the collection of its constructors which are added + as hints. - .. seealso:: :ref:`The Hints Databases for auto and eauto <thehintsdatabasesforautoandeauto>` + .. note:: -.. tacv:: auto using {+ @ident__i} {? with {+ @ident } } + The hints passed through the `using` clause are used in the same + way as if they were passed through a hint database. Consequently, + they use a weaker version of :tacn:`apply` and :n:`auto using @ident` + may fail where :n:`apply @ident` succeeds. - Uses lemmas :n:`@ident__i` in addition to hints. If :n:`@ident` is an - inductive type, it is the collection of its constructors which are added - as hints. + Given that this can be seen as counter-intuitive, it could be useful + to have an option to use full-blown :tacn:`apply` for lemmas passed + through the `using` clause. Contributions welcome! -.. tacv:: info_auto + .. tacv:: info_auto - Behaves like auto but shows the tactics it uses to solve the goal. This - variant is very useful for getting a better understanding of automation, or - to know what lemmas/assumptions were used. + Behaves like :tacn:`auto` but shows the tactics it uses to solve the goal. This + variant is very useful for getting a better understanding of automation, or + to know what lemmas/assumptions were used. -.. tacv:: debug auto - :name: debug auto + .. tacv:: debug auto + :name: debug auto - Behaves like :tacn:`auto` but shows the tactics it tries to solve the goal, - including failing paths. + Behaves like :tacn:`auto` but shows the tactics it tries to solve the goal, + including failing paths. -.. tacv:: {? info_}auto {? @num} {? using {+ @lemma}} {? with {+ @ident}} + .. tacv:: {? info_}auto {? @num} {? using {+ @lemma}} {? with {+ @ident}} - This is the most general form, combining the various options. + This is the most general form, combining the various options. .. tacv:: trivial :name: trivial - This tactic is a restriction of auto that is not recursive + This tactic is a restriction of :tacn:`auto` that is not recursive and tries only hints that cost `0`. Typically it solves trivial equalities like :g:`X=X`. -.. tacv:: trivial with {+ @ident} - :undocumented: - -.. tacv:: trivial with * - :undocumented: - -.. tacv:: trivial using {+ @lemma} - :undocumented: - -.. tacv:: debug trivial - :name: debug trivial - :undocumented: - -.. tacv:: info_trivial - :name: info_trivial - :undocumented: - -.. tacv:: {? info_}trivial {? using {+ @lemma}} {? with {+ @ident}} - :undocumented: + .. tacv:: trivial with {+ @ident} + trivial with * + trivial using {+ @lemma} + debug trivial + info_trivial + {? info_}trivial {? using {+ @lemma}} {? with {+ @ident}} + :name: _; _; _; debug trivial; info_trivial; _ + :undocumented: .. note:: - :tacn:`auto` either solves completely the goal or else leaves it - intact. :tacn:`auto` and :tacn:`trivial` never fail. - -The following options enable printing of informative or debug information for -the :tacn:`auto` and :tacn:`trivial` tactics: + :tacn:`auto` and :tacn:`trivial` either solve completely the goal or + else succeed without changing the goal. Use :g:`solve [ auto ]` and + :g:`solve [ trivial ]` if you would prefer these tactics to fail when + they do not manage to solve the goal. .. flag:: Info Auto Debug Auto Info Trivial Debug Trivial - :undocumented: -.. seealso:: :ref:`The Hints Databases for auto and eauto <thehintsdatabasesforautoandeauto>` + These options enable printing of informative or debug information for + the :tacn:`auto` and :tacn:`trivial` tactics. .. tacn:: eauto :name: eauto This tactic generalizes :tacn:`auto`. While :tacn:`auto` does not try resolution hints which would leave existential variables in the goal, - :tacn:`eauto` does try them (informally speaking, it usessimple :tacn:`eapply` - where :tacn:`auto` uses simple :tacn:`apply`). As a consequence, :tacn:`eauto` + :tacn:`eauto` does try them (informally speaking, it internally uses a tactic + close to :tacn:`simple eapply` instead of a tactic close to :tacn:`simple apply` + in the case of :tacn:`auto`). As a consequence, :tacn:`eauto` can solve such a goal: .. example:: .. coqtop:: all - Hint Resolve ex_intro. + Hint Resolve ex_intro : core. Goal forall P:nat -> Prop, P 0 -> exists n, P n. eauto. Note that ``ex_intro`` should be declared as a hint. -.. tacv:: {? info_}eauto {? @num} {? using {+ @lemma}} {? with {+ @ident}} + .. tacv:: {? info_}eauto {? @num} {? using {+ @lemma}} {? with {+ @ident}} - The various options for :tacn:`eauto` are the same as for :tacn:`auto`. + The various options for :tacn:`eauto` are the same as for :tacn:`auto`. -:tacn:`eauto` also obeys the following options: + :tacn:`eauto` also obeys the following options: -.. flag:: Info Eauto - Debug Eauto - :undocumented: + .. flag:: Info Eauto + Debug Eauto + :undocumented: -.. seealso:: :ref:`The Hints Databases for auto and eauto <thehintsdatabasesforautoandeauto>` + .. seealso:: :ref:`The Hints Databases for auto and eauto <thehintsdatabasesforautoandeauto>` .. tacn:: autounfold with {+ @ident} |