diff --git a/.obsidian/workspace b/.obsidian/workspace
index 256ce7696..e865d9c38 100644
--- a/.obsidian/workspace
+++ b/.obsidian/workspace
@@ -10,7 +10,7 @@
           {
             "id": "90ec1eb033ec1a7c",
             "type": "split",
-            "dimension": 15.903371917463513,
+            "dimension": 15.903371917463511,
             "children": [
               {
                 "id": "ae59c49b3be42d7f",
@@ -40,7 +40,7 @@
           {
             "id": "2df69b5c8478290b",
             "type": "leaf",
-            "dimension": 35.22898842476095,
+            "dimension": 17.614494212380475,
             "state": {
               "type": "markdown",
               "state": {
@@ -49,6 +49,18 @@
               }
             }
           },
+          {
+            "id": "20bdecf17922ea29",
+            "type": "leaf",
+            "dimension": 17.614494212380475,
+            "state": {
+              "type": "markdown",
+              "state": {
+                "file": "category theory basics.md",
+                "mode": "source"
+              }
+            }
+          },
           {
             "id": "ba944b0eac45b31d",
             "type": "leaf",
@@ -175,7 +187,7 @@
             "state": {
               "type": "backlink",
               "state": {
-                "file": "2021-05-30.md",
+                "file": "category theory basics.md",
                 "collapseAll": false,
                 "extraContext": false,
                 "sortOrder": "alphabetical",
@@ -192,7 +204,7 @@
             "state": {
               "type": "outline",
               "state": {
-                "file": "2021-05-30.md"
+                "file": "category theory basics.md"
               }
             }
           },
@@ -225,8 +237,9 @@
     "width": 300,
     "collapsed": true
   },
-  "active": "2df69b5c8478290b",
+  "active": "20bdecf17922ea29",
   "lastOpenFiles": [
+    "category theory basics.md",
     "2021-05-30.md",
     "cuello de burup.md",
     "blaine.md",
@@ -235,7 +248,6 @@
     "pre commit.md",
     "2021-05-29.md",
     "obsidian plugin.md",
-    "2021-05-28.md",
-    "patterns.md"
+    "2021-05-28.md"
   ]
 }
\ No newline at end of file
diff --git a/2021-05-30.md b/2021-05-30.md
index 65608f9e2..bde166dd5 100644
--- a/2021-05-30.md
+++ b/2021-05-30.md
@@ -2,4 +2,5 @@
 - [[cuello de burup]]
 - [[flatpak]]
 - [[do]]
-- 
\ No newline at end of file
+- [[category theory]]
+	- [[category theory basics]]
\ No newline at end of file
diff --git a/category theory basics.md b/category theory basics.md
new file mode 100644
index 000000000..e69de29bb