1 files changed, 68 insertions, 0 deletions
diff --git a/include/atp/strategy/calculus.h b/include/atp/strategy/calculus.h
new file mode 100644
index 0000000..ee8ee09
--- /dev/null
+++ b/include/atp/strategy/calculus.h
@@ -0,0 +1,68 @@
+/*
+ * 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 calculus.h
+/// @brief A Calculus bundles the exact set of inference rules + heuristics
+///        to use for a specific problem class.
+///
+/// Think of it as the "algorithm profile" that the Prover loads.
+/// Different problems get different calculi:
+///   - Pure propositional:  resolution + factoring only
+///   - FOL without equality: + full unification
+///   - FOL with equality:   + paramodulation + KBO ordering
+///   - Arithmetic:          + theory solver integration
+///
+/// This is the single point where search space control happens.
+
+#include "atp/rewrite/ordering.h"
+#include "atp/search/clause_queue.h"
+#include "atp/strategy/inference_rule.h"
+
+#include <memory>
+#include <string_view>
+#include <vector>
+
+namespace atp {
+
+/// A Calculus = a complete specification of how to search for a proof.
+/// The Prover is parameterized by this — it never hardcodes which rules to use.
+struct Calculus {
+    /// Name for logging (e.g., "superposition", "pure_resolution").
+    std::string name;
+
+    /// Generating rules (executed in order during the main loop).
+    std::vector<std::unique_ptr<GeneratingRule>> generating_rules;
+
+    /// Simplifying rules (applied to each new clause before enqueuing).
+    std::vector<std::unique_ptr<SimplifyingRule>> simplifying_rules;
+
+    /// Clause selection heuristic.
+    ClauseComparator comparator = bfsCompare;
+
+    /// Term ordering (nullptr if equality reasoning is disabled).
+    std::unique_ptr<TermOrdering> ordering = nullptr;
+
+    /// Resource limits.
+    size_t max_clauses = 100000;
+    size_t max_iterations = 500000;
+};
+
+}  // namespace atp