Commit Graph

106 Commits

Author SHA1 Message Date
69688d1d39
Add integer simplification rule
This adds the rule “(F in G) === (F = G) if F and G are integer
variables” to the simplification rule tableau
2018-04-29 22:28:42 +02:00
a70b1fb726
Print typing formulas for integer parameters
For every integer parameter of the visible predicates, this prints a
formula to the output that makes the integer type of that parameter
explicit.
2018-04-29 22:28:42 +02:00
b60c65a810
Add option to turn on integer variable detection 2018-04-29 22:28:42 +02:00
19e1e16e45
Implement integer variable detection
This adds support for detecting integer variables in formulas.

The idea is to iteratively assume variables to be noninteger and to
prove that this would lead to a false or erroneous result. If the proof
is successful, the variable is integer as a consequence.

The implementation consists of two parts. The first one is a visitor
class that recursively searches for all declared variables in a formula
and applies the second part, a custom check. Three such checks are
implemented.

The first one tests whether a predicate definition is falsified by
making a variable noninteger, in which case it can be concluded that the
variable in question is integer. The second one checks whether bound
variables in a quantified formula turn the quantified part false, again
to conclude that variables are integer. The third check consists in
testing if making a variable noninteger turns the entire formula
obtained from completion true. In this case, the statement can be
dropped and the variable is concluded to be integer as well.
2018-04-29 22:28:42 +02:00
43d2c153c7
Represent predicate parameters explicitly
This adds a vector of Parameter structs to PredicateDeclaration. In this
way, the domain of each parameter can be tracked individually.
2018-04-28 01:48:39 +02:00
e0509f725a
Replace SimplificationResult with OperationResult
This replaces the SimplificationResult enum class with OperationResult.
The rationale is that this type, which just reports whether or not an
operation actually changed the input data, is not simplification-
specific and will be used for integer variable detection as well.
2018-04-27 23:37:13 +02:00
48cf8ee3e0
Minor refactoring
Reorders some include directives lexicographically.
2018-04-27 23:35:43 +02:00
f7d99c82fa
Move Tristate class to Utils header
The Tristate class (representing truth values that are either true,
false, or unknown) will be used at multiple ends. This moves it to a
separate header in order to reuse it properly.
2018-04-27 23:19:42 +02:00
618189368c
Split functions from their declarations
This splits occurrences of functions from their declaration. This is
necessary to flag integer functions consistently and not just single
occurrences.
2018-04-27 17:59:10 +02:00
d0debc6ad1
Split predicates from their declarations
This refactoring separates predicates from their declarations. The
purpose of this is to avoid duplicating properties specific to the
predicate declaration and not its occurrences in the program.
2018-04-27 17:55:59 +02:00
e15a6b2e88
Remove Constant class
Constants are not a construct present in Clingo’s AST and were
unintentionally made part of anthem’s AST. This removes the unused
classes for clarity.
2018-04-27 17:08:41 +02:00
8c250f5c59
Support modulus operation (absolute value)
This adds support for computing the absolute value of a term along with
an according unit test.
2018-04-12 00:38:48 +02:00
797660d6de
Add new simplification rule
This adds the rule “(not F [comparison] G) === (F [negated comparison]
G)” to the simplification rule tableau.
2018-04-11 21:39:27 +02:00
40ddee8444
Add new simplification rule
This adds the rule “(not F or G) === (F -> G)” to the simplification
rule tableau.
2018-04-10 22:34:47 +02:00
6f7b021712
Add new simplification rule
This adds the rule “(not (F and G)) === (not F or not G)” to the
simplification rule tableau.
2018-04-10 22:34:47 +02:00
23624007ec
Add new simplification rule
This adds the rule “not not F === F” to the simplification rule tableau.
2018-04-10 22:34:47 +02:00
6d7b91c391
Add new simplification rule
This adds the rule “(F <-> (F and G)) === (F -> G)” to the
simplification rule tableau.
2018-04-10 22:34:47 +02:00
b88393655a
Iteratively apply simplification tableau rules
With this change, the tableau rules for simplifying formula are applied
iteratively until a fixpoint is reached.
2018-04-10 22:34:47 +02:00
c4c3156e77
Move simplification rule to tableau
This moves the rule “[primitive A] in [primitive B] === A = B” to the
simplification rule tableau.
2018-04-10 22:34:47 +02:00
107dae7287
Move simplification rule to tableau
This moves the rule “exists () (F) === F” to the simplification rule
tableau.
2018-04-10 22:34:47 +02:00
827d6e40fe
Move simplification rule to tableau
This moves the rule “[conjunction of only F] === F” to the
simplification rule tableau.
2018-04-10 22:34:47 +02:00
4a85fc4b23
Move simplification rule to tableau
This moves the rule “exists ... ([#true/#false]) === [#true/#false]” to
the simplification rule tableau along with “[empty conjunction] ===
2018-04-10 22:34:46 +02:00
7e3fc007c8
Move simplification rule to tableau
This moves the rule “exists X (X = t and F(X)) === exists () (F(t))” to
the simplification rule tableau.
2018-04-10 22:34:46 +02:00
5c5411c0ff
Implement simplification rule tableau
This implements a tableau containing simplification rules that can be
iteratively applied to input formulas until they remain unchanged.

First, this moves the rule “exists X (X = Y) === #true” to the tableau
as a reference implementation.
2018-04-10 22:34:46 +02:00
e64b2e70de
Remove unused captured lambda reference 2018-04-08 20:44:43 +02:00
c294a29cb2
Support placeholders with #external declarations
This adds support for declaring predicates as placeholders through the
“#external” directive in the input language of clingo.

Placeholders are not subject to completion. This prevents predicates
that represent instance-specific facts from being assumed as universally
false by default negation when translating an encoding.

This stretches clingo’s usual syntax a bit to make the implementation
lightweight. In order to declare a predicate with a specific arity as a
placeholder, the following statement needs to be added to the program:

    #external <predicate name>(<arity>).

Multiple unit tests cover cases where placeholders are used or not as
well as a more complex graph coloring example.
2018-04-08 20:28:57 +02:00
22238bb398
Switch to C++17
With C++17, optionals, an experimental language feature, were moved to
the “std” namespace. This makes C++17 mandatory and drops the now
obsolete “experimental” namespace.
2018-03-24 16:09:52 +01:00
5f8c144628
Fixed regression in simplifying predicates with more than one argument. 2017-06-12 18:27:39 +02:00
1f1006ea96
Corrected hiding predicates that are simple propositions. 2017-06-12 15:40:02 +02:00
a4cd133ba7
Correctly implemented hiding predicates with nested arguments. 2017-06-12 02:25:04 +02:00
bbbd0b65a4
Added new option --parentheses=full to make parsing the output easier. 2017-06-06 02:02:26 +02:00
0285c1cbbb
Renamed internal variables for clarity. 2017-06-06 01:44:44 +02:00
95984f0447
Added warning when attempting to use #show statements without completion. 2017-06-05 04:24:00 +02:00
7ae0a1f289
Removed unnecessary parentheses after simplification. 2017-06-05 03:58:39 +02:00
3b26580815
Minor formatting. 2017-06-05 03:54:17 +02:00
14abc37116
Implemented #show statements for completed output. 2017-06-05 03:02:22 +02:00
4fd143ef64
Added simplification rule “exists X (X = Y)” → “#true.” 2017-06-05 02:41:17 +02:00
7bf5d3867d
Minor clarification on side effects of a function. 2017-06-05 00:19:43 +02:00
ab71e8eb0a
Minor refactoring. 2017-06-04 20:55:25 +02:00
dcc504ebc0
Added another simplification step after completion. 2017-06-04 20:55:24 +02:00
381d55b6ed
Minor formatting fix. 2017-06-01 16:16:06 +02:00
2bc60d3eea
Started implementing support for #show statements. 2017-06-01 04:05:11 +02:00
cdcee897ec
Added missing error message when input file does not exist. 2017-06-01 03:29:09 +02:00
4baed6fbc6
Added back completion support. 2017-06-01 02:37:45 +02:00
0d8b1e94da
Refactored error handling. 2017-05-31 18:03:19 +02:00
1de0486989
Removed unnecessary namespace identifiers. 2017-05-30 18:13:31 +02:00
664a57ec68
Fixed issue with multi-layer variable stacks. 2017-05-30 18:09:33 +02:00
7aad8380d1
Refactored logging interface. 2017-05-30 17:19:26 +02:00
8214d7837a
Fixed incorrect variable declaration look-up in variable stack. 2017-05-30 16:40:14 +02:00
2964dd1309
Restricting variable stack look-up to user-defined variables. 2017-05-30 16:39:44 +02:00