1 files changed, 65 insertions, 0 deletions
diff --git a/proofsearch/src/core/symbol_table.cc b/proofsearch/src/core/symbol_table.cc
new file mode 100644
index 0000000..b707132
--- /dev/null
+++ b/proofsearch/src/core/symbol_table.cc
@@ -0,0 +1,65 @@
+/*
+ * 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/>.
+ */
+
+#include "atp/core/symbol_table.h"
+
+#include "atp/core/types.h"
+
+#include <cstddef>
+#include <cstdint>
+#include <stdexcept>
+#include <string>
+#include <string_view>
+
+namespace atp {
+
+SymbolId SymbolTable::intern(std::string_view name, SymbolKind kind, uint16_t arity, SortId sort) {
+    auto it = name_to_id_.find(name);
+    if (it != name_to_id_.end()) {
+        SymbolId const id = it->second;
+        SymbolInfo const& info = infos_[id];
+        if (info.kind_ != kind || info.arity_ != arity) {
+            throw std::runtime_error("Symbol kind or arity mismatch for: " + std::string(name));
+        }
+        return id;
+    }
+    auto new_id = static_cast<SymbolId>(infos_.size());
+    infos_.push_back(SymbolInfo{
+        .name_ = std::string(name), .kind_ = kind, .arity_ = arity, .sort_ = sort});
+    std::string_view const stable_name_view = infos_.back().name_;
+    name_to_id_.emplace(stable_name_view, new_id);
+    return new_id;
+}
+
+std::string_view SymbolTable::getName(SymbolId id) const {
+    return infos_[id].name_;
+}
+
+const SymbolInfo& SymbolTable::getInfo(SymbolId id) const {
+    return infos_[id];
+}
+
+bool SymbolTable::isVariable(SymbolId id) const {
+    return infos_[id].kind_ == SymbolKind::kVariable;
+}
+
+size_t SymbolTable::size() const {
+    return infos_.size();
+}
+
+}  // namespace atp