```python
# matrices from the document
R1 = [[1,0,1],[0,1,0],[1,0,0]]
R2 = [[1,1,0],[0,0,1],[1,0,1]]
R3 = [[1, 1, 1], [0, 0, 1], [0, 0, 1]]
R4 = [[1, 1, 0, 1], [1, 1, 0, 1], [0, 0, 1, 0], [1, 1, 0, 1]]
R5 = [[0, 1, 0], [0, 0, 1], [1, 0, 0]]
R6 = [[1, 1, 1], [0, 0, 1], [1, 0, 0]]

tests = [R1, R2, R3, R4, R5, R6]

CHAMPIONS = [[1,1,0,1,1],
            [0,1,0,0,0],
            [1,1,1,1,1],
            [1,1,0,1,1],
            [0,1,0,0,1]]
```


```python
# Check if a matrix is reflexive
def reflexive(R):
    for i in range(len(R)):
        if R[i][i] != 1:
            return False
    return True

# Check if a matrix is symmetric
def symmetrical(R):
    for i in range(len(R)):
        for j in range(len(R)):
            if R[i][j] != R[j][i]:
                return False
    return True

# Check if a matrix is anti-symmetric
def anti_symmetrical(R):
    for i in range(len(R)):
        for j in range(len(R)):
            if R[i][j] > 0 and R[j][i] > 0 and i != j:
                return False
    return True

# Check if a matrix is asymmetrical
def asymmetrical(R):
    for i in range(len(R)):
        for j in range(len(R)):
            if R[i][j] > 0 and R[j][i] > 0:
                return False
    return True

# Check if a matrix is irreflexive
def irreflexive(R):
    for i in range(len(R)):
        if R[i][i] > 0:
            return False
    return True

# Check if a matrix is transitive
def transitive(matrix):
    is_transitive = True
    for i in range(len(matrix)):
        for j in range(len(matrix)):
            if matrix[i][j] > 0:
                for k in range(len(matrix)):
                    if matrix[j][k] > 0:
                        is_transitive = is_transitive and matrix[i][k] > 0

    return is_transitive

# Check if a matrix is intransitive
def intransitive(matrix):
    is_transitive = True
    for i in range(len(matrix)):
        for j in range(len(matrix)):
            if matrix[i][j] > 0:
                for k in range(len(matrix)):
                    if matrix[j][k] > 0:
                        is_transitive = is_transitive and matrix[i][k] != 1

    return is_transitive

# Check if a matrix is non-transitive
def non_transitive(matrix):
    n = len(matrix)

    for i in range(n):
        for j in range(n):
            if matrix[i][j] > 0:
                for k in range(n):
                    if matrix[j][k] > 0 and matrix[i][k] == 0:
                        return True
    return False
```


```python
# Testing all the matrices from the slides

for i in range(len(tests)):
    print("--------------------------------------------------")
    print("Matrix: R", i+1)
    a = reflexive(tests[i])
    print("reflexive: ", a)
    a = irreflexive(tests[i])
    print("irreflexive: ", a)
    a = symmetrical(tests[i])
    print("symmetrical: ", a)
    a = anti_symmetrical(tests[i])
    print("anti_symmetrical: ", a)
    a = asymmetrical(tests[i])
    print("asymmetrical: ", a)
    a = transitive(tests[i])
    print("transitive: ", a)
    a = intransitive(tests[i])
    print("intransitive: ", a)
    a = non_transitive(tests[i])
    print("non_transitive: ", a)
```

    --------------------------------------------------
    Matrix: R 1
    reflexive:  False
    irreflexive:  False
    symmetrical:  True
    anti_symmetrical:  False
    asymmetrical:  False
    transitive:  False
    intransitive:  False
    non_transitive:  True
    --------------------------------------------------
    Matrix: R 2
    reflexive:  False
    irreflexive:  False
    symmetrical:  False
    anti_symmetrical:  True
    asymmetrical:  False
    transitive:  False
    intransitive:  False
    non_transitive:  True
    --------------------------------------------------
    Matrix: R 3
    reflexive:  False
    irreflexive:  False
    symmetrical:  False
    anti_symmetrical:  True
    asymmetrical:  False
    transitive:  True
    intransitive:  False
    non_transitive:  False
    --------------------------------------------------
    Matrix: R 4
    reflexive:  True
    irreflexive:  False
    symmetrical:  True
    anti_symmetrical:  False
    asymmetrical:  False
    transitive:  True
    intransitive:  False
    non_transitive:  False
    --------------------------------------------------
    Matrix: R 5
    reflexive:  False
    irreflexive:  True
    symmetrical:  False
    anti_symmetrical:  True
    asymmetrical:  True
    transitive:  False
    intransitive:  True
    non_transitive:  True
    --------------------------------------------------
    Matrix: R 6
    reflexive:  False
    irreflexive:  False
    symmetrical:  False
    anti_symmetrical:  False
    asymmetrical:  False
    transitive:  False
    intransitive:  False
    non_transitive:  True



```python
# Equivalence classes

def equivalence_classes(R):
    n = len(R)
    classes = []
    scores = []

    # Count number of (x,y) existing on each row
    for x in range(n):
        score = 0
        for y in range(n):
            if R[x][y] > 0:
                score += 1
        scores.append(score)

    lastScore = 0

    for i in range(n):
        max_score = 0
        max_index = 0
        for j in range(n):
            if scores[j] > max_score:
                max_score = scores[j]
                max_index = j

        if(max_score == lastScore):
            classes[len(classes)-1].append(max_index)
        else:
            # Add the class to the list of classes
            classes.append([max_index])

        lastScore = max_score
        scores[max_index] = 0

    return classes, scores

```


```python
print(equivalence_classes(CHAMPIONS))
```

    ([[2], [0, 3], [4], [1]], [0, 0, 0, 0, 0])



```python
def transitive_closure(adjacency_matrix):
    """
    Calculate the transitive closure of a directed graph represented as an adjacency matrix.

    Args:
    adjacency_matrix (list of lists): The adjacency matrix of the graph.

    Returns:
    list of lists: The transitive closure matrix.
    """
    n = len(adjacency_matrix)

    # Initialize the transitive closure matrix as a copy of the adjacency matrix
    closure_matrix = [row[:] for row in adjacency_matrix]

    # Perform the Floyd-Warshall algorithm to compute transitive closure
    for k in range(n):
        for i in range(n):
            for j in range(n):
                closure_matrix[i][j] = closure_matrix[i][j] or (closure_matrix[i][k] and closure_matrix[k][j])

    return closure_matrix

# Example usage:
adjacency_matrix = [
    [0, 1, 0, 0],
    [0, 0, 0, 1],
    [1, 0, 0, 0],
    [0, 0, 1, 0]
]

ex_cours = [
    [0, 0, 1, 0],
    [0, 0, 0, 0],
    [0, 1, 1, 1],
    [1, 0, 0, 0]
]

transitive_closure_matrix = transitive_closure(ex_cours)

# Print the transitive closure matrix
for row in transitive_closure_matrix:
    print(row)

```

    [1, 1, 1, 1]
    [0, 0, 0, 0]
    [1, 1, 1, 1]
    [1, 1, 1, 1]



```python
# Make transitive closure

transitive_closure_matrix = [
    [1, 0, 0, 0],
    [0, 1, 0, 1],
    [1, 0, 0, 0],
    [0, 0, 1, 1]
]

def transitive_closure(matrix):
    modification = True
    while modification:
        modification = False
        for i in range(len(matrix)):
            for j in range(len(matrix)):
                for k in range(len(matrix)):
                    if matrix[i][j] > 0 and matrix[j][k] > 0 and matrix[i][k] == 0:
                        matrix[i][k] = matrix[i][j] + matrix[j][k]
                        modification = True
                    else:
                        modification = False

    return matrix

full_closure = transitive_closure(ex_cours)

for row in full_closure:
    print(row)
```

    [3, 2, 1, 2]
    [0, 0, 0, 0]
    [2, 1, 1, 1]
    [1, 3, 2, 3]



```python
# Remove transitive closure

transitive_closure_matrix = [
[1, 0, 0, 0],
[0, 1, 2, 1],
[1, 0, 0, 0],
[2, 0, 1, 1]
]

m = [
    [1,1,1,1,1,1,1],
    [0,1,0,0,1,1,1],
    [0,0,1,0,0,0,1],
    [0,0,0,1,1,1,1],
    [0,0,0,0,1,1,1],
    [0,0,0,0,0,1,1],
    [0,0,0,0,0,0,1]
]

def remove_transitive_closure(matrix):
    n = len(matrix)
    modification = True

    while modification:
        # reset modification
        modification = False
        for i in range(n):
            for j in range(n):
                # checking if there is a path from i to j
                if matrix[i][j] > 0:
                    for k in range(j,n):
                        # checking if there is a path from i k to  to k
                        if matrix[i][k] > 0 and matrix[j][k] > 0:
                            matrix[i][k] = 0
                            modification = True
                            print("Removing ", i, k)
                            # restart while loop
                            break
                    if modification:
                        break

    return matrix

no_closure = remove_transitive_closure(transitive_closure_matrix)

for row in no_closure:
    print(row)

no_closure = remove_transitive_closure(m)

for row in no_closure:
    print(row)
```

    Removing  0 0
    Removing  1 1
    Removing  1 3
    Removing  3 3
    [0, 0, 0, 0]
    [0, 0, 2, 0]
    [1, 0, 0, 0]
    [2, 0, 1, 0]
    Removing  0 0
    Removing  1 1
    Removing  2 2
    Removing  3 3
    Removing  4 4
    Removing  5 5
    Removing  6 6
    Removing  0 4
    Removing  1 5
    Removing  3 5
    Removing  4 6
    Removing  0 6
    [0, 1, 1, 1, 0, 1, 0]
    [0, 0, 0, 0, 1, 0, 1]
    [0, 0, 0, 0, 0, 0, 1]
    [0, 0, 0, 0, 1, 0, 1]
    [0, 0, 0, 0, 0, 1, 0]
    [0, 0, 0, 0, 0, 0, 1]
    [0, 0, 0, 0, 0, 0, 0]

