diff --git a/2.md b/2.md
index eeca19e..a57f4ad 100644
--- a/2.md
+++ b/2.md
@@ -45,7 +45,11 @@ Lex라는 툴을 이용
 
 ## Specification
 
-Regular Expression
+**Regular Expression**
+
+* 여러가지에 사용됨 `grep`, `find`, `sed`, `awk`
+
+
 
 Multiple Matches
 
@@ -69,4 +73,48 @@ FSA를 이용함.
 DFA와 NFA의 표현력은 동일하나 DFA는 편하게 구현할 수 있다는 장점이 있음.
 NFA는 RE로부터 쉽게 변환가능하다는 장점이 있음.
 
-**Lexical ANalysis**
\ No newline at end of file
+**Lexical Analysis**
+
+`Lexical Spec -> RE -> NFA -> DFA -> Table`
+
+## Automation
+
+* `Lex`(`Flex`: faster implementation of Lex)
+* `Bison`
+
+### Lex/Flex
+
+* Definition Section
+  * can declear or include var, enumeration, using the code in between `%{`, `%}`
+  * provide names sub-rules for complex patterns used in **rules**
+
+* Rules Section
+  * Lexical Pattern 
+
+
+* User Function Section
+  * Copied to the Lex Program
+
+
+```c
+// example.l
+%{
+    #include <stdio.h>
+    int num_lines = 0;
+%}
+%%
+[ \t] {}
+a |
+an |
+the  {printf("%s: is an article\n", yytext)}
+[a-z]+ {printf("%s: ???\n", yytext)}
+%%
+main() {
+    yylex();1
+}
+```
+
+### Handwork
+
+* Thompson's construction (RE -> NFA)
+* Subset Construction(NFA -> DFA)
\ No newline at end of file
diff --git a/docker-compose.yml b/docker-compose.yml
new file mode 100644
index 0000000..4de9713
--- /dev/null
+++ b/docker-compose.yml
@@ -0,0 +1,12 @@
+version: '3.8'
+
+services:
+  compiler2025:
+    build: .
+    image: cs-compiler-hw:1.0
+    container_name: compiler2025
+    stdin_open: true
+    tty: true
+    working_dir: /work
+    volumes:
+      - .:/work
\ No newline at end of file
diff --git a/pdf/P0.pdf b/pdf/P0.pdf
new file mode 100644
index 0000000..4b182e9
Binary files /dev/null and b/pdf/P0.pdf differ