2 files changed, 28 insertions, 0 deletions
diff --git a/graph-checker/src/theorems/forbidden.rs b/graph-checker/src/theorems/forbidden.rs
new file mode 100644
index 0000000..615cdb1
--- /dev/null
+++ b/graph-checker/src/theorems/forbidden.rs
@@ -0,0 +1,27 @@
+use crate::Graph;
+
+pub fn theorem3_1(g: &Graph) -> bool {
+    let claw = Graph {
+        size: 4,
+        matrix: vec![
+            vec![0, 1, 1, 1],
+            vec![1, 0, 0, 0],
+            vec![1, 0, 0, 0],
+            vec![1, 0, 0, 0],
+        ],
+    };
+
+    let z1 = Graph {
+        size: 4,
+        matrix: vec![
+            vec![0, 1, 0, 0],
+            vec![1, 0, 1, 1],
+            vec![0, 1, 0, 1],
+            vec![0, 1, 1, 0],
+        ],
+    };
+
+    let forbidden = vec![claw, z1];
+
+    return g.is_2_connected() && g.is_free_of(&forbidden);
+}
diff --git a/graph-checker/src/theorems/mod.rs b/graph-checker/src/theorems/mod.rs
index 2737cbd..1135759 100644
--- a/graph-checker/src/theorems/mod.rs
+++ b/graph-checker/src/theorems/mod.rs
@@ -1,2 +1,3 @@
 pub mod basic;
+pub mod forbidden;
 pub mod toughness;