"""Print the pseudocode for the given algorithm."""

from urllib.request import urlopen

from IPython.display import Markdown

algorithm = algorithm.replace(' ', '-')

url = "https://raw.githubusercontent.com/aimacode/aima-pseudocode/master/md/{}.md".format(algorithm)

f = urlopen(url)

md = f.read().decode('utf-8')

md = md.split('\n', 1)[-1].strip()

md = '#' + md

"""Print the source code for the given function(s)."""

source_code = '\n\n'.join(getsource(fn) for fn in functions)

try:

from pygments.formatters import HtmlFormatter

from pygments.lexers import PythonLexer

from pygments import highlight

display(HTML(highlight(source_code, PythonLexer(), HtmlFormatter(full=True))))

except ImportError:

"""Plots the iris dataset in a 3D plot.

plt.rcParams.update(plt.rcParamsDefault)

fig = plt.figure()

ax = fig.add_subplot(111, projection='3d')

iris = DataSet(name="iris")

buckets = iris.split_values_by_classes()

features = ["Sepal Length", "Sepal Width", "Petal Length", "Petal Width"]

f1, f2, f3 = features[i], features[j], features[k]

a_setosa = [v[i] for v in buckets["setosa"]]

b_setosa = [v[j] for v in buckets["setosa"]]

c_setosa = [v[k] for v in buckets["setosa"]]

a_virginica = [v[i] for v in buckets["virginica"]]

b_virginica = [v[j] for v in buckets["virginica"]]

c_virginica = [v[k] for v in buckets["virginica"]]

a_versicolor = [v[i] for v in buckets["versicolor"]]

b_versicolor = [v[j] for v in buckets["versicolor"]]

c_versicolor = [v[k] for v in buckets["versicolor"]]

for c, m, sl, sw, pl in [('b', 's', a_setosa, b_setosa, c_setosa),

('g', '^', a_virginica, b_virginica, c_virginica),

('r', 'o', a_versicolor, b_versicolor, c_versicolor)]:

ax.scatter(sl, sw, pl, c=c, marker=m)

ax.set_xlabel(f1)

ax.set_ylabel(f2)

ax.set_zlabel(f3)

import os, struct

import array

import numpy as np

if fashion:

path = "aima-data/MNIST/Fashion"

plt.rcParams.update(plt.rcParamsDefault)

plt.rcParams['figure.figsize'] = (10.0, 8.0)

plt.rcParams['image.interpolation'] = 'nearest'

plt.rcParams['image.cmap'] = 'gray'

train_img_file = open(os.path.join(path, "train-images-idx3-ubyte"), "rb")

train_lbl_file = open(os.path.join(path, "train-labels-idx1-ubyte"), "rb")

test_img_file = open(os.path.join(path, "t10k-images-idx3-ubyte"), "rb")

test_lbl_file = open(os.path.join(path, 't10k-labels-idx1-ubyte'), "rb")

magic_nr, tr_size, tr_rows, tr_cols = struct.unpack(">IIII", train_img_file.read(16))

tr_img = array.array("B", train_img_file.read())

train_img_file.close()

magic_nr, tr_size = struct.unpack(">II", train_lbl_file.read(8))

tr_lbl = array.array("b", train_lbl_file.read())

train_lbl_file.close()

magic_nr, te_size, te_rows, te_cols = struct.unpack(">IIII", test_img_file.read(16))

te_img = array.array("B", test_img_file.read())

test_img_file.close()

magic_nr, te_size = struct.unpack(">II", test_lbl_file.read(8))

te_lbl = array.array("b", test_lbl_file.read())

test_lbl_file.close()

# print(len(tr_img), len(tr_lbl), tr_size)

# print(len(te_img), len(te_lbl), te_size)

train_img = np.zeros((tr_size, tr_rows * tr_cols), dtype=np.int16)

train_lbl = np.zeros((tr_size,), dtype=np.int8)

for i in range(tr_size):

train_img[i] = np.array(tr_img[i * tr_rows * tr_cols: (i + 1) * tr_rows * tr_cols]).reshape((tr_rows * te_cols))

train_lbl[i] = tr_lbl[i]

test_img = np.zeros((te_size, te_rows * te_cols), dtype=np.int16)

test_lbl = np.zeros((te_size,), dtype=np.int8)

for i in range(te_size):

test_img[i] = np.array(te_img[i * te_rows * te_cols: (i + 1) * te_rows * te_cols]).reshape((te_rows * te_cols))

test_lbl[i] = te_lbl[i]

if not fashion:

classes = digit_classes

else:

classes = fashion_classes

num_classes = len(classes)

for y, cls in enumerate(classes):

idxs = np.nonzero([i == y for i in labels])

idxs = np.random.choice(idxs[0], samples, replace=False)

for i, idx in enumerate(idxs):

plt_idx = i * num_classes + y + 1

plt.subplot(samples, num_classes, plt_idx)

plt.imshow(images[idx].reshape((28, 28)))

plt.axis("off")

if i == 0:

plt.title(cls)

if not fashion:

item_type = "Digit"

classes = digit_classes

else:

item_type = "Apparel"

classes = fashion_classes

num_classes = len(classes)

for y, cls in enumerate(classes):

idxs = np.nonzero([i == y for i in labels])

print(item_type, y, ":", len(idxs[0]), "images.")

ave_img = np.mean(np.vstack([images[i] for i in idxs[0]]), axis=0)

# print(ave_img.shape)

plt.subplot(1, num_classes, y + 1)

plt.imshow(ave_img.reshape((28, 28)))

plt.axis("off")

plt.title(cls)

"""ipywidgets interactive function supports single parameter as input.

def plot_grid_step(iteration):

data = U_over_time[iteration]

data = defaultdict(lambda: 0, data)

grid = []

for row in range(rows):

current_row = []

for column in range(columns):

current_row.append(data[(column, row)])

grid.append(current_row)

grid.reverse() # output like book

fig = plt.imshow(grid, cmap=plt.cm.bwr, interpolation='nearest')

plt.axis('off')

fig.axes.get_xaxis().set_visible(False)

fig.axes.get_yaxis().set_visible(False)

for col in range(len(grid)):

for row in range(len(grid[0])):

magic = grid[col][row]

fig.axes.text(row, col, "{0:.2f}".format(magic), va='center', ha='center')

plt.show()

"""Takes an input a sliderand returns callback function

def visualize_callback(visualize, time_step):

if visualize is True:

for i in range(slider.min, slider.max + 1):

slider.value = i

time.sleep(float(time_step))

"""Inherit from this class to manage the HTML canvas element in jupyter notebooks.

def __init__(self, varname, width=800, height=600, cid=None):

self.name = varname

self.cid = cid or varname

self.width = width

self.height = height

self.html = _canvas.format(self.cid, self.width, self.height, self.name)

self.exec_list = []

display_html(self.html)

def mouse_click(self, x, y):

"""Override this method to handle mouse click at position (x, y)"""

raise NotImplementedError

def mouse_move(self, x, y):

raise NotImplementedError

def execute(self, exec_str):

"""Stores the command to be executed to a list which is used later during update()"""

if not isinstance(exec_str, str):

print("Invalid execution argument:", exec_str)

self.alert("Received invalid execution command format")

prefix = "{0}_canvas_object.".format(self.cid)

self.exec_list.append(prefix + exec_str + ';')

def fill(self, r, g, b):

"""Changes the fill color to a color in rgb format"""

self.execute("fill({0}, {1}, {2})".format(r, g, b))

def stroke(self, r, g, b):

"""Changes the colors of line/strokes to rgb"""

self.execute("stroke({0}, {1}, {2})".format(r, g, b))

def strokeWidth(self, w):

"""Changes the width of lines/strokes to 'w' pixels"""

self.execute("strokeWidth({0})".format(w))

def rect(self, x, y, w, h):

"""Draw a rectangle with 'w' width, 'h' height and (x, y) as the top-left corner"""

self.execute("rect({0}, {1}, {2}, {3})".format(x, y, w, h))

def rect_n(self, xn, yn, wn, hn):

"""Similar to rect(), but the dimensions are normalized to fall between 0 and 1"""

x = round(xn * self.width)

y = round(yn * self.height)

w = round(wn * self.width)

h = round(hn * self.height)

self.rect(x, y, w, h)

def line(self, x1, y1, x2, y2):

"""Draw a line from (x1, y1) to (x2, y2)"""

self.execute("line({0}, {1}, {2}, {3})".format(x1, y1, x2, y2))

def line_n(self, x1n, y1n, x2n, y2n):

"""Similar to line(), but the dimensions are normalized to fall between 0 and 1"""

x1 = round(x1n * self.width)

y1 = round(y1n * self.height)

x2 = round(x2n * self.width)

y2 = round(y2n * self.height)

self.line(x1, y1, x2, y2)

def arc(self, x, y, r, start, stop):

"""Draw an arc with (x, y) as centre, 'r' as radius from angles 'start' to 'stop'"""

self.execute("arc({0}, {1}, {2}, {3}, {4})".format(x, y, r, start, stop))

def arc_n(self, xn, yn, rn, start, stop):

"""Similar to arc(), but the dimensions are normalized to fall between 0 and 1

x = round(xn * self.width)

y = round(yn * self.height)

r = round(rn * min(self.width, self.height))

self.arc(x, y, r, start, stop)

def clear(self):

"""Clear the HTML canvas"""

self.execute("clear()")

def font(self, font):

"""Changes the font of text"""

self.execute('font("{0}")'.format(font))

def text(self, txt, x, y, fill=True):

"""Display a text at (x, y)"""

if fill:

self.execute('fill_text("{0}", {1}, {2})'.format(txt, x, y))

else:

self.execute('stroke_text("{0}", {1}, {2})'.format(txt, x, y))

def text_n(self, txt, xn, yn, fill=True):

"""Similar to text(), but with normalized coordinates"""

x = round(xn * self.width)

y = round(yn * self.height)

self.text(txt, x, y, fill)

def alert(self, message):

"""Immediately display an alert"""

display_html('<script>alert("{0}")</script>'.format(message))

def update(self):

"""Execute the JS code to execute the commands queued by execute()"""

exec_code = "<script>\n" + '\n'.join(self.exec_list) + "\n</script>"

self.exec_list = []

"""Play a 3x3 TicTacToe game on HTML canvas"""

def __init__(self, varname, player_1='human', player_2='random',

width=300, height=350, cid=None):

valid_players = ('human', 'random', 'alpha_beta')

if player_1 not in valid_players or player_2 not in valid_players:

raise TypeError("Players must be one of {}".format(valid_players))

super().__init__(varname, width, height, cid)

self.ttt = TicTacToe()

self.state = self.ttt.initial

self.turn = 0

self.strokeWidth(5)

self.players = (player_1, player_2)

self.font("20px Arial")

self.draw_board()

def mouse_click(self, x, y):

player = self.players[self.turn]

if self.ttt.terminal_test(self.state):

if 0.55 <= x / self.width <= 0.95 and 6 / 7 <= y / self.height <= 6 / 7 + 1 / 8:

self.state = self.ttt.initial

self.turn = 0

self.draw_board()

return

if player == 'human':

x, y = int(3 * x / self.width) + 1, int(3 * y / (self.height * 6 / 7)) + 1

if (x, y) not in self.ttt.actions(self.state):

# Invalid move

return

move = (x, y)

elif player == 'alpha_beta':

move = alpha_beta_player(self.ttt, self.state)

else:

move = random_player(self.ttt, self.state)

self.state = self.ttt.result(self.state, move)

self.turn ^= 1

self.draw_board()

def draw_board(self):

self.clear()

self.stroke(0, 0, 0)

offset = 1 / 20

self.line_n(0 + offset, (1 / 3) * 6 / 7, 1 - offset, (1 / 3) * 6 / 7)

self.line_n(0 + offset, (2 / 3) * 6 / 7, 1 - offset, (2 / 3) * 6 / 7)

self.line_n(1 / 3, (0 + offset) * 6 / 7, 1 / 3, (1 - offset) * 6 / 7)

self.line_n(2 / 3, (0 + offset) * 6 / 7, 2 / 3, (1 - offset) * 6 / 7)

board = self.state.board

for mark in board:

if board[mark] == 'X':

self.draw_x(mark)

elif board[mark] == 'O':

self.draw_o(mark)

if self.ttt.terminal_test(self.state):

# End game message

utility = self.ttt.utility(self.state, self.ttt.to_move(self.ttt.initial))

if utility == 0:

self.text_n('Game Draw!', offset, 6 / 7 + offset)

else:

self.text_n('Player {} wins!'.format("XO"[utility < 0]), offset, 6 / 7 + offset)

# Find the 3 and draw a line

self.stroke([255, 0][self.turn], [0, 255][self.turn], 0)

for i in range(3):

if all([(i + 1, j + 1) in self.state.board for j in range(3)]) and \

len({self.state.board[(i + 1, j + 1)] for j in range(3)}) == 1:

self.line_n(i / 3 + 1 / 6, offset * 6 / 7, i / 3 + 1 / 6, (1 - offset) * 6 / 7)

if all([(j + 1, i + 1) in self.state.board for j in range(3)]) and \

len({self.state.board[(j + 1, i + 1)] for j in range(3)}) == 1:

self.line_n(offset, (i / 3 + 1 / 6) * 6 / 7, 1 - offset, (i / 3 + 1 / 6) * 6 / 7)

if all([(i + 1, i + 1) in self.state.board for i in range(3)]) and \

len({self.state.board[(i + 1, i + 1)] for i in range(3)}) == 1:

self.line_n(offset, offset * 6 / 7, 1 - offset, (1 - offset) * 6 / 7)

if all([(i + 1, 3 - i) in self.state.board for i in range(3)]) and \

len({self.state.board[(i + 1, 3 - i)] for i in range(3)}) == 1:

self.line_n(offset, (1 - offset) * 6 / 7, 1 - offset, offset * 6 / 7)

# restart button

self.fill(0, 0, 255)

self.rect_n(0.5 + offset, 6 / 7, 0.4, 1 / 8)

self.fill(0, 0, 0)

self.text_n('Restart', 0.5 + 2 * offset, 13 / 14)

else: # Print which player's turn it is

self.text_n("Player {}'s move({})".format("XO"[self.turn], self.players[self.turn]),

offset, 6 / 7 + offset)

self.update()

def draw_x(self, position):

self.stroke(0, 255, 0)

x, y = [i - 1 for i in position]

offset = 1 / 15

self.line_n(x / 3 + offset, (y / 3 + offset) * 6 / 7, x / 3 + 1 / 3 - offset, (y / 3 + 1 / 3 - offset) * 6 / 7)

self.line_n(x / 3 + 1 / 3 - offset, (y / 3 + offset) * 6 / 7, x / 3 + offset, (y / 3 + 1 / 3 - offset) * 6 / 7)

def draw_o(self, position):

self.stroke(255, 0, 0)

x, y = [i - 1 for i in position]

"""MinMax for Fig52Extended on HTML canvas"""

def __init__(self, varname, util_list, width=800, height=600, cid=None):

super.__init__(varname, width, height, cid)

self.utils = {node: util for node, util in zip(range(13, 40), util_list)}

self.game = Fig52Extended()

self.game.utils = self.utils

self.nodes = list(range(40))

self.l = 1 / 40

self.node_pos = {}

for i in range(4):

base = len(self.node_pos)

row_size = 3 ** i

for node in [base + j for j in range(row_size)]:

self.node_pos[node] = ((node - base) / row_size + 1 / (2 * row_size) - self.l / 2,

self.l / 2 + (self.l + (1 - 5 * self.l) / 3) * i)

self.font("12px Arial")

self.node_stack = []

self.explored = {node for node in self.utils}

self.thick_lines = set()

self.change_list = []

self.draw_graph()

self.stack_manager = self.stack_manager_gen()

def min_max(self, node):

game = self.game

player = game.to_move(node)

def max_value(node):

if game.terminal_test(node):

return game.utility(node, player)

self.change_list.append(('a', node))

self.change_list.append(('h',))

max_a = max(game.actions(node), key=lambda x: min_value(game.result(node, x)))

max_node = game.result(node, max_a)

self.utils[node] = self.utils[max_node]

x1, y1 = self.node_pos[node]

x2, y2 = self.node_pos[max_node]

self.change_list.append(('l', (node, max_node - 3 * node - 1)))

self.change_list.append(('e', node))

self.change_list.append(('p',))

self.change_list.append(('h',))

return self.utils[node]

def min_value(node):

if game.terminal_test(node):

return game.utility(node, player)

self.change_list.append(('a', node))

self.change_list.append(('h',))

min_a = min(game.actions(node), key=lambda x: max_value(game.result(node, x)))

min_node = game.result(node, min_a)

self.utils[node] = self.utils[min_node]

x1, y1 = self.node_pos[node]

x2, y2 = self.node_pos[min_node]

self.change_list.append(('l', (node, min_node - 3 * node - 1)))

self.change_list.append(('e', node))

self.change_list.append(('p',))

self.change_list.append(('h',))

return self.utils[node]

return max_value(node)

def stack_manager_gen(self):

self.min_max(0)

for change in self.change_list:

if change[0] == 'a':

self.node_stack.append(change[1])

elif change[0] == 'e':

self.explored.add(change[1])

elif change[0] == 'h':

yield

elif change[0] == 'l':

self.thick_lines.add(change[1])

elif change[0] == 'p':

self.node_stack.pop()

def mouse_click(self, x, y):

try:

self.stack_manager.send(None)

except StopIteration:

pass

self.draw_graph()

def draw_graph(self):

self.clear()

# draw nodes

self.stroke(0, 0, 0)

self.strokeWidth(1)

# highlight for nodes in stack

for node in self.node_stack:

x, y = self.node_pos[node]

self.fill(200, 200, 0)

self.rect_n(x - self.l / 5, y - self.l / 5, self.l * 7 / 5, self.l * 7 / 5)

for node in self.nodes:

x, y = self.node_pos[node]

if node in self.explored:

self.fill(255, 255, 255)

else:

self.fill(200, 200, 200)

self.rect_n(x, y, self.l, self.l)

self.line_n(x, y, x + self.l, y)

self.line_n(x, y, x, y + self.l)

self.line_n(x + self.l, y + self.l, x + self.l, y)

self.line_n(x + self.l, y + self.l, x, y + self.l)

self.fill(0, 0, 0)

if node in self.explored:

self.text_n(self.utils[node], x + self.l / 10, y + self.l * 9 / 10)

# draw edges

for i in range(13):

x1, y1 = self.node_pos[i][0] + self.l / 2, self.node_pos[i][1] + self.l

for j in range(3):

x2, y2 = self.node_pos[i * 3 + j + 1][0] + self.l / 2, self.node_pos[i * 3 + j + 1][1]

if i in [1, 2, 3]:

self.stroke(200, 0, 0)

else:

self.stroke(0, 200, 0)

if (i, j) in self.thick_lines:

self.strokeWidth(3)

else:

self.strokeWidth(1)

self.line_n(x1, y1, x2, y2)

"""Alpha-beta pruning for Fig52Extended on HTML canvas"""

def __init__(self, varname, util_list, width=800, height=600, cid=None):

super().__init__(varname, width, height, cid)

self.utils = {node: util for node, util in zip(range(13, 40), util_list)}

self.game = Fig52Extended()

self.game.utils = self.utils

self.nodes = list(range(40))

self.l = 1 / 40

self.node_pos = {}

for i in range(4):

base = len(self.node_pos)

row_size = 3 ** i

for node in [base + j for j in range(row_size)]:

self.node_pos[node] = ((node - base) / row_size + 1 / (2 * row_size) - self.l / 2,

3 * self.l / 2 + (self.l + (1 - 6 * self.l) / 3) * i)

self.font("12px Arial")

self.node_stack = []

self.explored = {node for node in self.utils}

self.pruned = set()

self.ab = {}

self.thick_lines = set()

self.change_list = []

self.draw_graph()

self.stack_manager = self.stack_manager_gen()

def alpha_beta_search(self, node):

game = self.game

player = game.to_move(node)

# Functions used by alpha_beta

def max_value(node, alpha, beta):

if game.terminal_test(node):

self.change_list.append(('a', node))

self.change_list.append(('h',))

self.change_list.append(('p',))

return game.utility(node, player)

v = -np.inf

self.change_list.append(('a', node))

self.change_list.append(('ab', node, v, beta))

self.change_list.append(('h',))

for a in game.actions(node):

min_val = min_value(game.result(node, a), alpha, beta)

if v < min_val:

v = min_val

max_node = game.result(node, a)

self.change_list.append(('ab', node, v, beta))

if v >= beta:

self.change_list.append(('h',))

self.pruned.add(node)

break

alpha = max(alpha, v)

self.utils[node] = v

if node not in self.pruned:

self.change_list.append(('l', (node, max_node - 3 * node - 1)))

self.change_list.append(('e', node))

self.change_list.append(('p',))

self.change_list.append(('h',))

return v

def min_value(node, alpha, beta):

if game.terminal_test(node):

self.change_list.append(('a', node))

self.change_list.append(('h',))

self.change_list.append(('p',))

return game.utility(node, player)

v = np.inf

self.change_list.append(('a', node))

self.change_list.append(('ab', node, alpha, v))

self.change_list.append(('h',))

for a in game.actions(node):

max_val = max_value(game.result(node, a), alpha, beta)

if v > max_val:

v = max_val

min_node = game.result(node, a)

self.change_list.append(('ab', node, alpha, v))

if v <= alpha:

self.change_list.append(('h',))

self.pruned.add(node)

break

beta = min(beta, v)

self.utils[node] = v

if node not in self.pruned:

self.change_list.append(('l', (node, min_node - 3 * node - 1)))

self.change_list.append(('e', node))

self.change_list.append(('p',))

self.change_list.append(('h',))

return v

return max_value(node, -np.inf, np.inf)

def stack_manager_gen(self):

self.alpha_beta_search(0)

for change in self.change_list:

if change[0] == 'a':

self.node_stack.append(change[1])

elif change[0] == 'ab':

self.ab[change[1]] = change[2:]

elif change[0] == 'e':

self.explored.add(change[1])

elif change[0] == 'h':

yield

elif change[0] == 'l':

self.thick_lines.add(change[1])

elif change[0] == 'p':

self.node_stack.pop()

def mouse_click(self, x, y):

try:

self.stack_manager.send(None)

except StopIteration:

pass

self.draw_graph()

def draw_graph(self):

self.clear()

# draw nodes

self.stroke(0, 0, 0)

self.strokeWidth(1)

# highlight for nodes in stack

for node in self.node_stack:

x, y = self.node_pos[node]

# alpha > beta

if node not in self.explored and self.ab[node][0] > self.ab[node][1]:

self.fill(200, 100, 100)

else:

self.fill(200, 200, 0)

self.rect_n(x - self.l / 5, y - self.l / 5, self.l * 7 / 5, self.l * 7 / 5)

for node in self.nodes:

x, y = self.node_pos[node]

if node in self.explored:

if node in self.pruned:

self.fill(50, 50, 50)

else:

self.fill(255, 255, 255)

else:

self.fill(200, 200, 200)

self.rect_n(x, y, self.l, self.l)

self.line_n(x, y, x + self.l, y)

self.line_n(x, y, x, y + self.l)

self.line_n(x + self.l, y + self.l, x + self.l, y)

self.line_n(x + self.l, y + self.l, x, y + self.l)

self.fill(0, 0, 0)

if node in self.explored and node not in self.pruned:

self.text_n(self.utils[node], x + self.l / 10, y + self.l * 9 / 10)

# draw edges

for i in range(13):

x1, y1 = self.node_pos[i][0] + self.l / 2, self.node_pos[i][1] + self.l

for j in range(3):

x2, y2 = self.node_pos[i * 3 + j + 1][0] + self.l / 2, self.node_pos[i * 3 + j + 1][1]

if i in [1, 2, 3]:

self.stroke(200, 0, 0)

else:

self.stroke(0, 200, 0)

if (i, j) in self.thick_lines:

self.strokeWidth(3)

else:

self.strokeWidth(1)

self.line_n(x1, y1, x2, y2)

# display alpha and beta

for node in self.node_stack:

if node not in self.explored:

x, y = self.node_pos[node]

alpha, beta = self.ab[node]

self.text_n(alpha, x - self.l / 2, y - self.l / 10)

self.text_n(beta, x + self.l, y - self.l / 10)

"""fol_bc_ask() on HTML canvas"""

def __init__(self, varname, kb, query, width=800, height=600, cid=None):

super().__init__(varname, width, height, cid)

self.kb = kb

self.query = query

self.l = 1 / 20

self.b = 3 * self.l

bc_out = list(self.fol_bc_ask())

if len(bc_out) == 0:

self.valid = False

else:

self.valid = True

graph = bc_out[0][0][0]

s = bc_out[0][1]

while True:

new_graph = subst(s, graph)

if graph == new_graph:

break

graph = new_graph

self.make_table(graph)

self.context = None

self.draw_table()

def fol_bc_ask(self):

KB = self.kb

query = self.query

def fol_bc_or(KB, goal, theta):

for rule in KB.fetch_rules_for_goal(goal):

lhs, rhs = parse_definite_clause(standardize_variables(rule))

for theta1 in fol_bc_and(KB, lhs, unify_mm(rhs, goal, theta)):

yield ([(goal, theta1[0])], theta1[1])

def fol_bc_and(KB, goals, theta):

if theta is None:

pass

elif not goals:

yield ([], theta)

else:

first, rest = goals[0], goals[1:]

for theta1 in fol_bc_or(KB, subst(theta, first), theta):

for theta2 in fol_bc_and(KB, rest, theta1[1]):

yield (theta1[0] + theta2[0], theta2[1])

return fol_bc_or(KB, query, {})

def make_table(self, graph):

table = []