diff --git a/.obsidian/plugins/breadcrumbs/data.json b/.obsidian/plugins/breadcrumbs/data.json
index abd4ce54..d6b8e853 100644
--- a/.obsidian/plugins/breadcrumbs/data.json
+++ b/.obsidian/plugins/breadcrumbs/data.json
@@ -286,7 +286,7 @@
           "prevs"
         ],
         "lock_view": false,
-        "lock_path": "filtre convergent.md",
+        "lock_path": "cardinal.md",
         "custom_sort_fields": false,
         "custom_sort_field_labels": []
       },
diff --git a/cardinal.md b/cardinal.md
new file mode 100644
index 00000000..a9974f87
--- /dev/null
+++ b/cardinal.md
@@ -0,0 +1,17 @@
+---
+up:
+  - "[[théorie des ensemble NBC]]"
+tags:
+  - s/maths/logique
+aliases:
+---
+
+> [!definition] Définition
+> On définit les cardinaux à partir des ensembles :
+> $0 = \emptyset$
+> $1 = \{ \emptyset \}$
+> $2 = \{ \emptyset, \{ \emptyset \} \}$
+> $3 = \{ \emptyset, \{ \emptyset \}, \{ \emptyset, \{  \emptyset \} \} \}$
+> $\vdots$
+> $n^{+} = n \cup \{ n \}$
+^definition