From 0041f2263c34b6ab76155493b076cdb30061461c Mon Sep 17 00:00:00 2001
From: reiniscirpons <rc234@st-andrews.ac.uk>
Date: Wed, 1 May 2024 16:29:24 +0100
Subject: [PATCH] Add more coverage tests for Sims

---
 tests/test-sims.cpp | 94 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 94 insertions(+)

diff --git a/tests/test-sims.cpp b/tests/test-sims.cpp
index a09dcd815..4a36da7f8 100644
--- a/tests/test-sims.cpp
+++ b/tests/test-sims.cpp
@@ -18,6 +18,7 @@
 
 #include "libsemigroups/detail/stl.hpp"
 #include "libsemigroups/word-graph.hpp"
+#include <cstdint>
 #define CATCH_CONFIG_ENABLE_PAIR_STRINGMAKER
 #define CATCH_CONFIG_ENABLE_TUPLE_STRINGMAKER
 
@@ -4006,6 +4007,99 @@ namespace libsemigroups {
     s.add_pruner(ip);
     REQUIRE(s.number_of_congruences(12) == 12);  // computed using GAP
   }
+
+  LIBSEMIGROUPS_TEST_CASE("Sims1",
+                          "124",
+                          "Right congruence checking",
+                          "[quick][low-index]") {
+    Presentation<word_type> p;
+    p.alphabet(01_w);
+    p.contains_empty_word(true);
+    presentation::add_rule(p, 000_w, 11_w);
+    presentation::add_rule(p, 001_w, 10_w);
+
+    word_graph_type wg;
+
+    // Wrong alphabet size
+    wg = to_word_graph<node_type>(3, {{1, 1, 1}, {2, 2, 2}, {2, 2, 2}});
+    wg.number_of_active_nodes(3);
+    REQUIRE(!sims::is_right_congruence(p, wg));
+
+    // Incomplete
+    wg = to_word_graph<node_type>(2, {{1, 1}, {1, UNDEFINED}});
+    wg.number_of_active_nodes(2);
+    REQUIRE(!sims::is_right_congruence(p, wg));
+
+    // Incompatible
+    wg = to_word_graph<node_type>(2, {{1, 1}, {1, 0}});
+    wg.number_of_active_nodes(2);
+    REQUIRE(!sims::is_right_congruence(p, wg));
+    REQUIRE_THROWS_AS(sims::validate_right_congruence(p, wg),
+                      LibsemigroupsException);
+
+    // Works
+    wg = to_word_graph<node_type>(4, {{1, 2}, {2, 2}, {3, 3}, {3, 3}});
+    wg.number_of_active_nodes(4);
+    REQUIRE(sims::is_right_congruence(p, wg));
+
+    // Non maximal
+    wg = to_word_graph<node_type>(2, {{1, 1}, {1, 0}});
+    wg.number_of_active_nodes(2);
+    REQUIRE(!sims::is_maximal_right_congruence(p, wg));
+    wg = to_word_graph<node_type>(4, {{1, 2}, {2, 2}, {3, 3}, {3, 3}});
+    wg.number_of_active_nodes(4);
+    REQUIRE(!sims::is_maximal_right_congruence(p, wg));
+    wg = to_word_graph<node_type>(1, {{0, 0}});
+    wg.number_of_active_nodes(1);
+    REQUIRE(!sims::is_maximal_right_congruence(p, wg));
+
+    // Is maximal
+    wg = to_word_graph<node_type>(2, {{1, 1}, {1, 1}});
+    wg.number_of_active_nodes(2);
+    REQUIRE(sims::is_maximal_right_congruence(p, wg));
+  }
+
+  LIBSEMIGROUPS_TEST_CASE("Sims2",
+                          "125",
+                          "Two-sided congruence checking",
+                          "[quick][low-index]") {
+    Presentation<word_type> p;
+    p.alphabet(01_w);
+    p.contains_empty_word(true);
+    presentation::add_rule(p, 000_w, 11_w);
+    presentation::add_rule(p, 001_w, 10_w);
+
+    word_graph_type wg;
+
+    // Wrong alphabet size
+    wg = to_word_graph<node_type>(3, {{1, 1, 1}, {2, 2, 2}, {2, 2, 2}});
+    wg.number_of_active_nodes(3);
+    REQUIRE(!sims::is_two_sided_congruence(p, wg));
+
+    // Incomplete
+    wg = to_word_graph<node_type>(2, {{1, 1}, {1, UNDEFINED}});
+    wg.number_of_active_nodes(2);
+    REQUIRE(!sims::is_two_sided_congruence(p, wg));
+
+    // Incompatible
+    wg = to_word_graph<node_type>(2, {{1, 1}, {1, 0}});
+    wg.number_of_active_nodes(2);
+    REQUIRE(!sims::is_two_sided_congruence(p, wg));
+    REQUIRE_THROWS_AS(sims::validate_two_sided_congruence(p, wg),
+                      LibsemigroupsException);
+
+    // Not compatible with X_Gamma
+    wg = to_word_graph<node_type>(4, {{1, 2}, {2, 2}, {3, 3}, {3, 3}});
+    wg.number_of_active_nodes(4);
+    REQUIRE(!sims::is_two_sided_congruence(p, wg));
+    REQUIRE_THROWS_AS(sims::validate_two_sided_congruence(p, wg),
+                      LibsemigroupsException);
+
+    // Works
+    wg = to_word_graph<node_type>(2, {{1, 1}, {1, 1}});
+    wg.number_of_active_nodes(2);
+    REQUIRE(sims::is_two_sided_congruence(p, wg));
+  }
 }  // namespace libsemigroups
 
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