diff --git a/.obsidian/workspace.json b/.obsidian/workspace.json
index d8b2698..9830f63 100644
--- a/.obsidian/workspace.json
+++ b/.obsidian/workspace.json
@@ -69,8 +69,7 @@
       }
     ],
     "direction": "horizontal",
-    "width": 300,
-    "collapsed": true
+    "width": 300
   },
   "right": {
     "id": "d8cc89662b1baf06",
@@ -86,7 +85,6 @@
             "state": {
               "type": "backlink",
               "state": {
-                "file": "4a1s/RAS/T - Aula 3.md",
                 "collapseAll": false,
                 "extraContext": false,
                 "sortOrder": "alphabetical",
@@ -103,7 +101,6 @@
             "state": {
               "type": "outgoing-link",
               "state": {
-                "file": "4a1s/RAS/T - Aula 3.md",
                 "linksCollapsed": false,
                 "unlinkedCollapsed": true
               }
@@ -126,7 +123,7 @@
             "state": {
               "type": "outline",
               "state": {
-                "file": "4a1s/RAS/T - Aula 3.md"
+                "file": "Excalidraw/Drawing 2023-09-27 17.15.52.excalidraw.md"
               }
             }
           },
@@ -159,10 +156,13 @@
       "digitalgarden:Digital Garden Publication Center": false
     }
   },
-  "active": "98e0287d38212615",
+  "active": "3ca14d4a6c304083",
   "lastOpenFiles": [
-    "4a1s/Excalidraw/RAS/process.excalidraw.md",
     "4a1s/RAS/T - Aula 3.md",
+    "Excalidraw/Drawing 2023-09-27 17.15.52.excalidraw.md",
+    "4a1s/RAS/PL - Aula 2.md",
+    "4a1s/RAS/T - Aula 1.md",
+    "4a1s/Excalidraw/RAS/process.excalidraw.md",
     "4a1s/Excalidraw/RAS",
     "4a1s/Excalidraw/Untitled.md",
     "Excalidraw/doodles.excalidraw.md",
@@ -171,11 +171,9 @@
     "4a1s/CP/T - Aula 2 - 19 Setembro.md",
     "4a1s/MFES/T - Aula 2.md",
     "4a1s/MFES/PL - Aula 1.md",
-    "4a1s/RAS/PL - Aula 2.md",
     "4a1s/CP/PL - Aula 2.md",
     "4a1s/RAS/PL - Aula 1.md",
     "4a1s/RAS/T - Aula 2.md",
-    "4a1s/RAS/T - Aula 1.md",
     "4a1s/RAS/Notas Projeto RAS.md",
     "Excalidraw",
     "4a1s/DAA/PL - Aula 1.md",
@@ -188,7 +186,6 @@
     "4a1s/Excalidraw/ASCN/server-group.excalidraw.md",
     "4a1s/Excalidraw/ASCN/Replication.excalidraw.md",
     "4a1s/Excalidraw/ASCN/proxy.excalidraw.md",
-    "4a1s/Excalidraw/ASCN/Partitioning.excalidraw.md",
     "-.32118",
     "4a1s/ASCN/T",
     "4a1s/ASCN/T.32118",
diff --git a/4a1s/RAS/T - Aula 3.md b/4a1s/RAS/T - Aula 3.md
index 3fa953d..a8a6621 100644
--- a/4a1s/RAS/T - Aula 3.md	
+++ b/4a1s/RAS/T - Aula 3.md	
@@ -1,4 +1,8 @@
-26 de Setembro 2023 - #RAS 
+---
+dg-publish: true
+---
+
+🌫 26 de Setembro 2023 - #RAS 
 
 ## Definition of Requirements Engineering
 - **Requirements engineering** designates all the activities related to requirements discovery, negotiation, documentation, and maintenance.
@@ -55,9 +59,29 @@ Process Scheme: [[process.excalidraw]]
 
 ### 4. Negotiation
 - Requirements engineering involves communication and negotiation among various stakeholders.
-- It is inevitable that conflict situations arise among the requirements. One needs to promote negotiation mechanisms among the stakeholders. Its result can have a significant impact on the acceptance of the final system.
+- Conflict situations between requirements are inevitable. One needs to promote negotiation mechanisms among the stakeholders. Its result can have a significant impact on the acceptance of the final system.
 - Another form of handling conflicts consists in adopting prioritisation techniques, to sustain the choice of the requirements subset to be implemented at each instant.
 
 ### 5. Documentation
 - Requirements documents serve as the principal reference to the subsequent phases of the development process.
-- 
+- The requirements document is organised according to two distinct perspectives:
+	1. user requirements - describe the expectations and the necessities of the users;
+	2. system requirements - establish the agreement between the client and the development team.
+- The structure/formality of the documentation should vary in line with the system characteristics and the adopted process.
+
+### 6. Validation
+- The objective is to ensure that the requirements define the system desired by the client.
+- One should examine the requirements document through inspections or technical reviews of the specifications, to evaluate if it describes the intended system.
+- Validation is a testing activity.
+- While the requirements engineering activities are conducted, it is necessary to execute tasks that allow requirements to be verified and validated.
+
+### 7. Management
+- The requirements set is constantly changing.
+- Mechanisms to manage that instability context are needed, in order to evaluate the impact that the changes in the requirements can have.
+- One must reject changes that imply: a significative increase in cost; a postponement of the final delievery; a system devaluation for the user.
+- The requirements management activity seeks to aid the development team to identify, control and trace the requirements and their changes.
+
+
+## Difficulties
+1. Communication problems between requirements engineers and users are common.
+2. Changes in the requirements must be considered as a natural fact.