The main motivation is to break the remove the dependency frontends/lean <-- bindings/lua.
This dependency is undesirable because we want to expose the frontends/lean parser and pretty printer objects at bindings/lua.
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
The new hash code has the property that given expr_cell * c1 and expr_cell * c2,
if c1 != c2 then there is a high propbability that c1->hash_alloc() != c2->hash_alloc().
The structural hash code hash() does not have this property because we may have
c1 != c2, but c1 and c2 are structurally equal.
The new hash code is only compatible with pointer equality.
By compatible we mean, if c1 == c2, then c1->hash_alloc() == c2->hash_alloc().
This property is obvious because hash_alloc() does not have side-effects.
The test tests/lua/big.lua exposes the problem fixed by this commit.
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
Instead of having m_interrupted flags in several components. We use a thread_local global variable.
The new approach is much simpler to get right since there is no risk of "forgetting" to propagate
the set_interrupt method to sub-components.
The plan is to support set_interrupt methods and m_interrupted flags only in tactic objects.
We need to support them in tactics and tacticals because we want to implement combinators/tacticals such as (try_for T M) that fails if tactic T does not finish in M ms.
For example, consider the tactic:
try-for (T1 ORELSE T2) 5
It tries the tactic (T1 ORELSE T2) for 5ms.
Thus, if T1 does not finish after 5ms an interrupt request is sent, and T1 is interrupted.
Now, if you do not have a m_interrupted flag marking each tactic, the ORELSE combinator will try T2.
The set_interrupt method for ORELSE tactical should turn on the m_interrupted flag.
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
For example, this feature is useful when displaying the integer value 10 with coercions enabled. In this case, we want to display "nat_to_int 10" instead of "10".
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
It is incorrect to apply substitutions during normalization.
The problem is that we do not have support for tracking justifications in the normalizer. So, substitutions were being silently applied during normalization. Thus, the correctness of the conflict resolution in the elaboration was being affected.
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
We need that when we normalize the assignment in a metavariable environment.
That is, we replace metavariable in a substitution with other assignments.
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
elaborator was not handling max constraints where one of the arguments was a Bool. Example:
ctx |- max(Bool, Type) == ?M
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
We may miss solutions, but the solutions found are much more readable.
For example, without this option, for elaboration problem
Theorem Example4 (a b c d e : N) (H: (a = b ∧ b = e ∧ b = c) ∨ (a = d ∧ d = c)) : (h a c) = (h c a) :=
DisjCases H
(fun H1 : _,
let AeqC := Trans (Conjunct1 H1) (Conjunct2 (Conjunct2 H1))
in CongrH AeqC (Symm AeqC))
(fun H1 : _,
let AeqC := Trans (Conjunct1 H1) (Conjunct2 H1)
in CongrH AeqC (Symm AeqC))
the elaborator generates
Theorem Example4 (a b c d e : N) (H : a = b ∧ b = e ∧ b = c ∨ a = d ∧ d = c) : (h a c) = (h c a) :=
DisjCases
H
(λ H1 : if
Bool
(if Bool (a = b) (if Bool (if Bool (if Bool (b = e) (if Bool (b = c) ⊥ ⊤) ⊤) ⊥ ⊤) ⊥ ⊤) ⊤)
⊥
⊤,
let AeqC := Trans (Conjunct1 H1) (Conjunct2 (Conjunct2 H1)) in CongrH AeqC (Symm AeqC))
(λ H1 : if Bool (if Bool (a = d) (if Bool (d = c) ⊥ ⊤) ⊤) ⊥ ⊤,
let AeqC := Trans (Conjunct1 H1) (Conjunct2 H1) in CongrH AeqC (Symm AeqC))
The solution is correct, but it is not very readable. The problem is that the elaborator expands the definitions of \/ and /\.
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
Motivations:
- We have been writing several comments of the form "... trace/justification..." and "this trace object justify ...".
- Avoid confusion with util/trace.h
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
This normalization rule is not really a computational rule.
It is essentially encoding the reflexivity axiom as computation.
It can also be abaused. For example, with this rule,
the following definition is valid:
Theorem Th : a = a := Refl b
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
The printer and formatter objects are not trusted code.
We moved them to the kernel to be able to provide them as an argument to the trace objects.
Another motivation is to eliminate the kernel_exception_formatter hack.
With the formatter in the kernel, we can implement the pretty printer for kernel exceptions as a virtual method.
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
Trace objects will be used to justify steps performed by engines such as the elaborator. We use them to implement non-chronological backtracking in the elaborator. They are also use to justify to the user why something did not work.
The unification constraints are in the kernel because the type checker may create them when type checking a term containing metavariables.
Remark: a minimalistic kernel does not need to include metavariables, unification constraints, nor trace objects. We include these objects in our kernel to minimize code duplication.
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
- Use hierarchical names instead of unsigned integers to identify metavariables.
- Associate type with metavariable.
- Replace metavar_env with substitution.
- Rename meta_ctx --> local_ctx
- Rename meta_entry --> local_entry
- Disable old elaborator
- Rename unification_problems to unification_constraints
- Add metavar_generator
- Fix metavar unit tests
- Modify type checker to use metavar_generator
- Fix placeholder module
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
