diff --git a/ex4/practical_assignment4.pdf b/ex4/practical_assignment4.pdf
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diff --git a/ex4/seating-arrangement.py b/ex4/seating-arrangement.py
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+++ b/ex4/seating-arrangement.py
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+# coding: utf-8
+import os, sys
+from z3 import *
+
+from itertools import combinations
+
+pretty_print = True
+
+# get the playground information
+if len(sys.argv) != 2:
+    print("Usage: python3 seating-arrangement.py <wedding-file>")
+    sys.exit(0)
+
+def faulty_line(line, num):
+    print("Faulty input at line " + str(num) + ". Ignoring '" + line + "'")
+
+# data structures prepared for you
+guests = set()
+friends = []
+foes = []
+longest_name_len = 0
+
+def add_to_guest_list(a,b=None):
+    guests.add(a)
+    if b != None:
+        guests.add(b)
+
+def longest_name(a,b=None):
+    global longest_name_len
+    if len(a) > longest_name_len: longest_name_len = len(a)
+    if b != None and len(b) > longest_name_len : longest_name_len = len(b)
+
+solver = Solver()
+
+################################### Parse Guests and Constraints ####################################
+
+# todo: create a sort Guest
+
+with open(sys.argv[1]) as f:
+    wedding = f.read()
+    wedding = wedding.strip().split("\n")
+    linenum = 0
+    for line in wedding:
+        linenum += 1
+        if line[0] == '#':
+            continue
+        if line.rstrip():
+            info = line.split(" ")
+
+            if len(info) == 1:
+                # todo: initialize Z3 Const and add single guest to 'guests' list
+                add_to_guest_list()
+                longest_name(info[0])
+                continue
+
+            if len(info) != 3:
+                faulty_line(line, linenum)
+                continue
+
+            # todo: initialize Z3 Consts and add two guests to 'guests' list
+            longest_name(info[0], info[2])
+            if info[1] == "dislikes":
+                # todo add pair of guests as foes
+                pass
+            elif info[1] == "likes":
+                # todo add pair of guests as friends
+            else:
+                faulty_line(line, linenum)
+                continue
+            # todo: add two guests to 'guests' list
+
+################################### Wedding Guests ####################################
+
+# todo create an uninterpreted function from your sort to integers
+
+# todo create a function which returns whether two guests are sitting next to each other
+def neigbours(a, b):
+    pass
+
+# todo all guests must be seated at the big table
+# check the indices here
+for guest in guests:
+    pass
+
+# todo no two guests should sit on the same position
+for combination in combinations(guests,2): #todo
+    pass
+
+#todo friends should be neigbours
+for (a,b) in friends: #todo
+    pass
+
+#todo foes should not be neigbours
+for (a,b) in foes: # todo
+    pass
+
+# check satisfiability
+res = solver.check()
+if res != sat:
+    print("unsat")
+    sys.exit(1)
+m = solver.model()
+
+################################################################################
+
+
+arrangement = ["" for guest in range(len(guests))]
+for guest in guests:
+    arrangement[m.evaluate(position(guest),model_completion=True).as_long()] = guest.decl().name()
+
+def print_table():
+    side_length = round(len(guests)/4)
+    top    = arrangement[0:side_length]
+    right  = arrangement[side_length:2*side_length]
+    bottom = arrangement[2*side_length:3*side_length]
+    left   = arrangement[3*side_length:]
+    while len(left) < len(right):
+        left.append("")
+    while len(right) < len(left):
+        right.append("")
+    table_line_length = longest_name_len + 1
+
+    print("\n")
+
+    top_row = ""
+    top_row += (longest_name_len + 1) * " "
+    for top_guest in top:
+        top_row += top_guest + " "
+        table_line_length += len(top_guest) + 1
+    print(top_row)
+    print((longest_name_len + 1) * " " + table_line_length * "-")
+
+    first_element = True
+    for left_guest, right_guest in zip(reversed(left), right):
+        row = ""
+        if not first_element:
+            row += longest_name_len * " "
+            row += "|" + ">"* (table_line_length) + "|"
+            print(row)
+            row = ""
+        else:
+            first_element = False
+        row += left_guest.rjust(longest_name_len) + "|" + "<"* (table_line_length) + "|" + right_guest
+        print(row)
+
+    print((longest_name_len + 1) * " " + table_line_length * "-")
+    bottom_row = ""
+    bottom_row += (longest_name_len + 1) * " "
+    for bottom_guest in reversed(bottom):
+        bottom_row += bottom_guest + " "
+    print(bottom_row)
+    print("\n")
+
+if(pretty_print):
+    print_table()
+print("Seating plan:")
+print(arrangement)
diff --git a/ex4/wedding0.txt b/ex4/wedding0.txt
new file mode 100644
index 0000000..f868b4f
--- /dev/null
+++ b/ex4/wedding0.txt
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+Patric dislikes Ada
+Patric dislikes Katie
+Patric dislikes Bob
+Ada
+John likes Alice
+Bob likes Andrea
+Andrea
+Alice
+Ada likes Julia
+Ada likes Katie
+Robert