diff --git a/lab-3/token.h b/lab-3/token.h
index 8b40b70..176d506 100644
--- a/lab-3/token.h
+++ b/lab-3/token.h
@@ -1,6 +1,5 @@
 typedef enum {
   TOKEN_EOF = 0,
-  // Identification Keywords
   TOKEN_IDENTIFICATION,
   TOKEN_KEYWORD_DIVISION,
   TOKEN_KEYWORD_DATA,
@@ -8,8 +7,6 @@ typedef enum {
   TOKEN_PROGRAM_ID,
   TOKEN_WORKING_STORAGE,
   TOKEN_PROCEDURE,
-
-  // Program Keywords
   TOKEN_DISPLAY,
   TOKEN_STOP,
   TOKEN_RUN,
@@ -28,11 +25,7 @@ typedef enum {
   TOKEN_KEYWORD_VALUE,
   TOKEN_KEYWORD_COMPUTE,
   TOKEN_KEYWORD_FUNCTION,
-
-  // Identifiers
   TOKEN_IDENT,
-
-  // Data types
   TOKEN_STRING,
   TOKEN_INTEGER,
   TOKEN_PICTURE,
@@ -40,19 +33,14 @@ typedef enum {
   TOKEN_NUMERIC,
   TOKEN_SIGNED_NUMERIC,
   TOKEN_IMPLIED_DECIMAL,
-  // https://ibmmainframes.com/about393.html
   TOKEN_COMPUTATION_LEVEL_0,
   TOKEN_COMPUTATION_LEVEL_1,
   TOKEN_COMPUTATION_LEVEL_2,
   TOKEN_COMPUTATION_LEVEL_3,
-
-  // Grammar
   TOKEN_LEFT_PARENTHESIS,
   TOKEN_RIGHT_PARENTHESIS,
   TOKEN_DOT,
   TOKEN_COMMENT,
-
-  // Operators
   TOKEN_ADD,
   TOKEN_SUB,
   TOKEN_MULTIPLY,
diff --git a/lab-4/samples/hello-world.cbl b/lab-4/samples/hello-world.cbl
new file mode 100644
index 0000000..737f19e
--- /dev/null
+++ b/lab-4/samples/hello-world.cbl
@@ -0,0 +1,5 @@
+IDENTIFICATION DIVISION.
+PROGRAM-ID. HELLO-WORLD.
+PROCEDURE DIVISION.
+    DISPLAY 'Hello World!'
+STOP RUN.
diff --git a/lab-4/samples/program.c b/lab-4/samples/program.c
deleted file mode 100644
index bc5edc5..0000000
--- a/lab-4/samples/program.c
+++ /dev/null
@@ -1 +0,0 @@
-2020+4;
\ No newline at end of file
diff --git a/lab-4/samples/quadratic-snippet.cbl b/lab-4/samples/quadratic-snippet.cbl
new file mode 100644
index 0000000..ab76e40
--- /dev/null
+++ b/lab-4/samples/quadratic-snippet.cbl
@@ -0,0 +1,35 @@
+       *> Code altered from https://www.quora.com/What-is-a-COBOL-program-that-will-solve-a-quadratic-equation
+       *> Program finds the roots to a simple quadratic equation
+
+       IDENTIFICATION DIVISION.
+       PROGRAM-ID. QuadraticSolver.
+       DATA DIVISION.
+           WORKING-STORAGE SECTION.
+           77 a PIC S9(5)V9(5) COMP-3 VALUE 1.
+           77 b PIC S9(5)V9(5) COMP-3 VALUE 5.
+           77 c PIC S9(5)V9(5) COMP-3 VALUE 6.
+           77 discriminant PIC S9(5)V9(5) COMP-3.
+           77 root1 PIC S9(5)V9(5) COMP-3.
+           77 root2 PIC S9(5)V9(5) COMP-3.
+           77 square-root-discriminant PIC S9(5)V9(5) COMP-3.
+
+       PROCEDURE DIVISION. *> program begins here
+           DISPLAY "EQUATION: (1x^2) + 5x + 6 = 0" 
+           COMPUTE discriminant = (b ** 2) - (4 * a * c)
+
+           IF discriminant > 0
+               COMPUTE square-root-discriminant = FUNCTION SQRT(discriminant)
+               COMPUTE root1 = (-b + square-root-discriminant) / (2 * a)
+               COMPUTE root2 = (-b - square-root-discriminant) / (2 * a)
+               DISPLAY "The equation has two distinct real roots: "
+               DISPLAY "Root 1: " root1
+               DISPLAY "Root 2: " root2
+
+           ELSE IF discriminant = 0
+               COMPUTE root1 = -b / (2 * a)
+               DISPLAY "The equation has one real root: "
+               DISPLAY "Root: " root1
+           ELSE
+               DISPLAY "The equation has no real roots."
+
+       STOP RUN.
diff --git a/lab-4/samples/sorting-snippet.cbl b/lab-4/samples/sorting-snippet.cbl
new file mode 100644
index 0000000..8324e47
--- /dev/null
+++ b/lab-4/samples/sorting-snippet.cbl
@@ -0,0 +1,55 @@
+IDENTIFICATION DIVISION.
+PROGRAM-ID. sorting.
+DATA DIVISION.
+WORKING-STORAGE SECTION.
+    01  WS-SORT-AREA.
+    05  WS-SORT-TABLE.
+        10  WS-SORT-ROW PIC X(10) OCCURS 100.
+    05  WS-TEMP-ROW     PIC X(10).
+    05  WS-ROW-MAX      PIC S9(4) COMP VALUE 100.
+    05  WS-SORT-MAX     PIC S9(4) COMP.
+    05  WS-I            PIC S9(4) COMP.
+    05  WS-J            PIC S9(4) COMP.
+    05  WS-INDEX        PIC S9(4) COMP.
+
+PROCEDURE DIVISION.
+*> Initialize test data
+    MOVE "30" TO WS-SORT-ROW(1)
+    MOVE "10" TO WS-SORT-ROW(2)
+    MOVE "50" TO WS-SORT-ROW(3)
+    MOVE "20" TO WS-SORT-ROW(4)
+    MOVE "40" TO WS-SORT-ROW(5)
+    MOVE 5 TO WS-SORT-MAX
+
+*> * Display original array
+    DISPLAY "Original Array Contents:"
+    DISPLAY "---------------------"
+    PERFORM VARYING WS-INDEX FROM 1 BY 1
+        UNTIL WS-INDEX > WS-SORT-MAX
+        DISPLAY "Element " WS-INDEX ": " WS-SORT-ROW(WS-INDEX)
+    END-PERFORM
+    DISPLAY SPACE
+
+*> * Simplified bubble sort
+    PERFORM VARYING WS-I FROM 1 BY 1 
+        UNTIL WS-I > WS-SORT-MAX - 1
+        PERFORM VARYING WS-J FROM 1 BY 1 
+            UNTIL WS-J > WS-SORT-MAX - WS-I
+            IF WS-SORT-ROW(WS-J) > WS-SORT-ROW(WS-J + 1)
+                MOVE WS-SORT-ROW(WS-J) TO WS-TEMP-ROW
+                MOVE WS-SORT-ROW(WS-J + 1) TO WS-SORT-ROW(WS-J)
+                MOVE WS-TEMP-ROW TO WS-SORT-ROW(WS-J + 1)
+            END-IF
+        END-PERFORM
+    END-PERFORM
+
+*> * Display sorted array
+    DISPLAY "Sorted Array Contents:"
+    DISPLAY "--------------------"
+    PERFORM VARYING WS-INDEX FROM 1 BY 1
+        UNTIL WS-INDEX > WS-SORT-MAX
+        DISPLAY "Element " WS-INDEX ": " WS-SORT-ROW(WS-INDEX)
+    END-PERFORM.
+
+    STOP RUN.
+    
\ No newline at end of file