blob: 8cadaa6fdba892799956aa468a9eac1f234770a5 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
|
/*
* richard-atp-engine: A saturation-based automated theorem prover for first-order logic.
* Copyright (C) 2026 Richard Qin
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
#pragma once
/// @file discrim_tree.h
/// @brief Perfect Discrimination Tree for fast term indexing.
///
/// Used by subsumption and resolution to quickly find candidate clauses
/// whose literals unify with a query term. Supports three query modes:
/// - Unifiable: find terms that can be unified with the query
/// - Instances: find terms that are instances of the query (more specific)
/// - Generalizations: find terms that are generalizations of the query (more general)
#include "atp/core/clause.h"
#include "atp/core/term_bank.h"
#include "atp/core/types.h"
#include <vector>
namespace atp {
/// A match result from the discrimination tree.
struct IndexMatch {
ClauseId clause_id;
size_t lit_index;
};
/// A discrimination tree index over terms.
/// Supports insertion and three types of retrieval queries.
class DiscrimTree {
public:
explicit DiscrimTree(const TermBank& bank);
/// Insert a term (identified by its TermId) with an associated clause/literal ref.
void insert(TermId term, ClauseId clause_id, size_t lit_index);
/// Retrieve all entries whose indexed term is unifiable with `query`.
[[nodiscard]] std::vector<IndexMatch> queryUnifiable(TermId query) const;
/// Retrieve all entries whose indexed term is an instance of `query`.
/// (query is more general, indexed term is more specific)
[[nodiscard]] std::vector<IndexMatch> queryInstances(TermId query) const;
/// Retrieve all entries whose indexed term is a generalization of `query`.
/// (indexed term is more general, query is more specific)
/// This is the key operation for forward subsumption.
[[nodiscard]] std::vector<IndexMatch> queryGeneralizations(TermId query) const;
/// Remove all entries for a given clause.
void removeClause(ClauseId clause_id);
/// Number of indexed entries.
[[nodiscard]] size_t size() const;
private:
const TermBank& bank_;
// TODO: Phase 3 implementation — trie node arena
};
} // namespace atp
|
