1 files changed, 17 insertions, 0 deletions
diff --git a/graph-checker/src/theorems/toughness.rs b/graph-checker/src/theorems/toughness.rs
new file mode 100644
index 0000000..e659901
--- /dev/null
+++ b/graph-checker/src/theorems/toughness.rs
@@ -0,0 +1,17 @@
+use crate::Graph;
+
+pub fn theorem15(g: &Graph, toughness: f64, min_degree: f64) -> bool {
+    let max_ind_cutset_size = g.max_independent_cutset().cardinality as f64;
+    let third_of_size = g.size as f64 / 3.0;
+    let tmp = if third_of_size > max_ind_cutset_size - 1.0 {
+        third_of_size
+    } else {
+        max_ind_cutset_size - 1.0
+    };
+
+    return toughness >= 1.0 && min_degree >= tmp;
+}
+
+pub fn theorem25(g: &Graph, toughness: f64, min_degree: f64) -> bool {
+    return min_degree > g.size as f64 / (toughness + 1.0) - 1.0;
+}