def __init__(self, q_kind='default_nothing', **options):
        self.derived = True

        # The call to the mother class __init__() method will set the
        # fields matching optional arguments which are so far:
        # self.q_kind, self.q_subkind
        # plus self.options (modified)
        Q_Structure.__init__(self, q_kind, AVAILABLE_Q_KIND_VALUES, **options)
        # The purpose of this next line is to get the possibly modified
        # value of **options
        options = self.options

        init_caller = INIT_CALLER[q_kind]

        self.expandable_objct = None

        self.numeric_aux = None

        if q_kind == 'any_basic_expd':
            randomly_drawn = randomly.decimal_0_1()
            if randomly_drawn <= 0.25:
                self.expandable_objct = Expandable((RANDOMLY, 'monom0_polyn1'),
                                                   randomly_reversed=0.5)
            elif randomly_drawn <= 0.50:
                self.expandable_objct = Expandable((RANDOMLY, 'monom1_polyn1'),
                                                   randomly_reversed=0.5)
            else:
                self.expandable_objct = Expandable((RANDOMLY, 'polyn1_polyn1'))

        elif q_kind in ['monom0_polyn1', 'monom1_polyn1']:
            self.expandable_objct = Expandable((RANDOMLY, q_kind),
                                               randomly_reversed=0.5)
        elif q_kind == 'monom01_polyn1':
            self.expandable_objct = Expandable(
                (RANDOMLY, randomly.pop(['monom0_polyn1', 'monom1_polyn1'])),
                randomly_reversed=0.5)

        elif q_kind == 'polyn1_polyn1':
            self.expandable_objct = Expandable((RANDOMLY, 'polyn1_polyn1'))

        elif q_kind == 'sum_of_any_basic_expd':
            if self.q_subkind in ['harder', 'with_a_binomial']:
                # __
                choices = ['monom0_polyn1', 'monom1_polyn1']

                drawn_types = list()
                drawn_types.append(randomly.pop(choices))

                if self.q_subkind == 'with_a_binomial':
                    drawn_types.append('any_binomial')
                else:
                    drawn_types.append('minus_polyn1_polyn1')

                aux_expd_list = list()

                for t in drawn_types:
                    if t == 'any_binomial':
                        aux_expd_list.append(
                            BinomialIdentity((RANDOMLY, 'any'), **options))
                    else:
                        aux_expd_list.append(Expandable((RANDOMLY, t)))

                final_list = list()
                for i in range(len(aux_expd_list)):
                    final_list.append(randomly.pop(aux_expd_list))

                self.expandable_objct = Sum(final_list)

            elif self.q_subkind == 'easy':
                choices = ['monom0_polyn1', 'monom1_polyn1']

                aux_expd_list = list()
                aux_expd_list.append(
                    Expandable((RANDOMLY, randomly.pop(choices))))

                if randomly.heads_or_tails():
                    aux_expd_list.append(Expandable((RANDOMLY, 'sign_exp')))
                else:
                    aux_expd_list.append(
                        Monomial((RANDOMLY, 15, randomly.integer(0, 2))))

                final_list = list()
                for i in range(len(aux_expd_list)):
                    final_list.append(randomly.pop(aux_expd_list))

                self.expandable_objct = Sum(final_list)

            else:
                choices = [
                    'monom0_polyn1', 'monom0_polyn1', 'monom1_polyn1',
                    'monom1_polyn1', 'polyn1_polyn1', 'minus_polyn1_polyn1'
                ]

                drawn_types = list()
                drawn_types.append(randomly.pop(choices))
                drawn_types.append(randomly.pop(choices))

                aux_expd_list = list()

                for element in drawn_types:
                    aux_expd_list.append(Expandable((RANDOMLY, element)))

                aux_expd_list.append(Monomial((RANDOMLY, 15, 2)))

                final_list = list()
                for i in range(len(aux_expd_list)):
                    final_list.append(randomly.pop(aux_expd_list))

                self.expandable_objct = Sum(final_list)

        elif q_kind in ['sign_expansion', 'sign_expansion_short_test']:
            sign_exp_kind = options.get('sign_exp_kind', 0)

            if q_kind == 'sign_expansion_short_test':
                sign_exp_kind = 1

            if sign_exp_kind == 0:
                sign_exp_kind = randomly.integer(1, 5)

            # Creation of the terms
            aux_terms_list = list()

            aux_expd_1 = Expandable((Monomial(
                (randomly.sign(), 1, 0)), Polynomial((RANDOMLY, 15, 2, 2))))

            aux_expd_2 = Expandable((Monomial(
                (randomly.sign(), 1, 0)), Polynomial((RANDOMLY, 15, 2, 2))))

            aux_expd_3 = Expandable((Monomial(
                (randomly.sign(), 1, 0)), Polynomial((RANDOMLY, 15, 2, 2))))

            long_aux_expd = Expandable((Monomial(
                (randomly.sign(), 1, 0)), Polynomial((RANDOMLY, 15, 2, 3))))

            if q_kind == 'sign_expansion_short_test':
                long_aux_expd = Expandable((Monomial(
                    ('-', 1, 0)), Polynomial((RANDOMLY, 15, 2, 3))))

            aux_monomial = Monomial((RANDOMLY, 15, 2))

            # 1st kind: a Monomial and ± (long Polynomial)
            # (like in a short test)
            if sign_exp_kind == 1:
                aux_terms_list.append(long_aux_expd)
                aux_terms_list.append(aux_monomial)

            # 2d kind: ± (x+3) ± (4x - 7)
            elif sign_exp_kind == 2:
                aux_terms_list.append(aux_expd_1)
                aux_terms_list.append(aux_expd_2)

            # 3d kind: ± (x+3) ± (4x - 7) ± (x² - 5x)
            elif sign_exp_kind == 3:
                aux_terms_list.append(aux_expd_1)
                aux_terms_list.append(aux_expd_2)
                aux_terms_list.append(aux_expd_3)

            # 4th kind: ± (x+3) ± (4x - 7) ± Monomial
            elif sign_exp_kind == 4:
                aux_terms_list.append(aux_expd_1)
                aux_terms_list.append(aux_expd_2)
                aux_terms_list.append(aux_monomial)

            # 5th kind: ± (x+3) ± Monomial ± (long Polynomial)
            elif sign_exp_kind == 5:
                aux_terms_list.append(aux_expd_2)
                aux_terms_list.append(aux_monomial)
                aux_terms_list.append(long_aux_expd)

            # add as many possibilities as wanted,
            # don't forget to increase the last number here:
            # sign_exp_kind = randomly.integer(1, 5) (what's a bit above)

            # Now let's distribute the terms randomly
            final_terms_list = list()
            for i in range(len(aux_terms_list)):
                final_terms_list.append(randomly.pop(aux_terms_list))

            self.expandable_objct = Sum(final_terms_list)

        elif q_kind in [
                'numeric_sum_square', 'numeric_difference_square',
                'numeric_squares_difference'
        ]:
            # __
            self.expandable_objct = init_caller(
                (options['couple'][0], options['couple'][1]), **options)
            if q_kind in ['numeric_sum_square', 'numeric_difference_square']:
                self.numeric_aux = Sum(
                    [options['couple'][0], options['couple'][1]]).reduce_()
                self.numeric_aux.set_exponent(2)

            else:  # squares_difference's case
                aux1 = Sum([options['couple'][0],
                            options['couple'][1]]).reduce_()
                temp = options['couple'][1].clone()
                temp.set_sign('-')
                aux2 = Sum([options['couple'][0], temp]).reduce_()
                self.numeric_aux = Product([aux1, aux2])

        else:
            if q_kind == 'any_binomial':
                q_kind = 'any'

            self.expandable_objct = init_caller((RANDOMLY, q_kind), **options)

        # Creation of the expression:
        number = 0
        if 'expression_number' in options                                     \
           and is_.a_natural_int(options['expression_number']):
            # __
            number = options['expression_number']
        self.expression = Expression(number, self.expandable_objct)
        if self.numeric_aux is not None:
            self.numeric_aux = Expression(number, self.numeric_aux)
Esempio n. 2
0
    def __init__(self, q_kind='default_nothing', **options):
        self.derived = True

        # The call to the mother class __init__() method will set the
        # fields matching optional arguments which are so far:
        # self.q_kind, self.q_subkind
        # plus self.options (modified)
        Q_Structure.__init__(self, q_kind, AVAILABLE_Q_KIND_VALUES, **options)
        # The purpose of this next line is to get the possibly modified
        # value of **options
        options = self.options

        # That's the number of the question, not of the expressions it might
        # contain !
        self.number = ""
        if 'number_of_questions' in options:
            self.number = options['number_of_questions']

        self.objct = None

        # 1st OPTION
        if q_kind == 'fraction_simplification':
            root = randomly.integer(2,
                                    19,
                                    weighted_table=[
                                        0.225, 0.225, 0, 0.2, 0, 0.2, 0, 0, 0,
                                        0.07, 0, 0.0375, 0, 0, 0, 0.0375, 0,
                                        0.005
                                    ])

            factors_list = [j + 1 for j in range(10)]

            ten_power_factor1 = 1
            ten_power_factor2 = 1

            if 'with_ten_powers' in options \
               and is_.a_number(options['with_ten_powers']) \
               and options['with_ten_powers'] <= 1 \
               and options['with_ten_powers'] >= 0:
                # __
                if randomly.decimal_0_1() < options['with_ten_powers']:
                    ten_powers_list = [10, 10, 100, 100]
                    ten_power_factor1 = randomly.pop(ten_powers_list)
                    ten_power_factor2 = randomly.pop(ten_powers_list)

            self.objct = Fraction(
                ('+', root * randomly.pop(factors_list) * ten_power_factor1,
                 root * randomly.pop(factors_list) * ten_power_factor2))

        # 2d & 3d OPTIONS
        # Fractions Products | Quotients
        elif q_kind in ['fractions_product', 'fractions_quotient']:
            # In some cases, the fractions will be generated
            # totally randomly
            if randomly.decimal_0_1() < 0:
                lil_box = [n + 2 for n in range(18)]
                a = randomly.pop(
                    lil_box,
                    weighted_table=FRACTION_PRODUCT_AND_QUOTIENT_TABLE)
                b = randomly.pop(
                    lil_box,
                    weighted_table=FRACTION_PRODUCT_AND_QUOTIENT_TABLE)

                lil_box = [n + 2 for n in range(18)]
                c = randomly.pop(
                    lil_box,
                    weighted_table=FRACTION_PRODUCT_AND_QUOTIENT_TABLE)
                d = randomly.pop(
                    lil_box,
                    weighted_table=FRACTION_PRODUCT_AND_QUOTIENT_TABLE)

                f1 = Fraction((randomly.sign(plus_signs_ratio=0.75),
                               Item((randomly.sign(plus_signs_ratio=0.80), a)),
                               Item(
                                   (randomly.sign(plus_signs_ratio=0.80), b))))

                f2 = Fraction((randomly.sign(plus_signs_ratio=0.75),
                               Item((randomly.sign(plus_signs_ratio=0.80), c)),
                               Item(
                                   (randomly.sign(plus_signs_ratio=0.80), d))))

                # f1 = f1.simplified()
                # f2 = f2.simplified()

            # In all other cases (80%), we'll define a "seed" a plus two
            # randomly numbers i and j to form the Product | Quotient:
            # a×i / b  ×   c / a × j
            # Where b is a randomly number coprime to a×i
            # and c is a randomly number coprime to a×j
            else:
                a = randomly.integer(2, 8)
                lil_box = [i + 2 for i in range(7)]
                i = randomly.pop(lil_box)
                j = randomly.pop(lil_box)

                b = randomly.coprime_to(a * i, [n + 2 for n in range(15)])
                c = randomly.not_coprime_to(b, [n + 2 for n in range(30)],
                                            excepted=a * j)

                f1 = Fraction(
                    (randomly.sign(plus_signs_ratio=0.75),
                     Item((randomly.sign(plus_signs_ratio=0.80), a * i)),
                     Item((randomly.sign(plus_signs_ratio=0.80), b))))

                f2 = Fraction(
                    (randomly.sign(plus_signs_ratio=0.75),
                     Item((randomly.sign(plus_signs_ratio=0.80), c)),
                     Item((randomly.sign(plus_signs_ratio=0.80), a * j))))

                if randomly.heads_or_tails():
                    f3 = f1.clone()
                    f1 = f2.clone()
                    f2 = f3.clone()

                if q_kind == 'fractions_quotient':
                    f2 = f2.invert()

            if q_kind == 'fractions_product':
                self.objct = Product([f1, f2])

            elif q_kind == 'fractions_quotient':
                self.objct = Quotient(('+', f1, f2, 1, 'use_divide_symbol'))

        # 4th OPTION
        # Fractions Sums
        elif q_kind == 'fractions_sum':
            randomly_position = randomly\
                .integer(0, 16, weighted_table=FRACTIONS_SUMS_SCALE_TABLE)

            chosen_seed_and_generator = FRACTIONS_SUMS_TABLE[randomly_position]

            seed = randomly.integer(2, chosen_seed_and_generator[1])

            # The following test is only intended to avoid having "high"
            # results too often. We just check if the common denominator
            # will be higher than 75 (arbitrary) and if yes, we redetermine
            # it once. We don't do it twice since we don't want to totally
            # forbid high denominators.
            if seed * chosen_seed_and_generator[0][0] \
                    * chosen_seed_and_generator[0][1] >= 75:
                # __
                seed = randomly.integer(2, chosen_seed_and_generator[1])

            lil_box = [0, 1]
            gen1 = chosen_seed_and_generator[0][lil_box.pop()]
            gen2 = chosen_seed_and_generator[0][lil_box.pop()]

            den1 = Item(gen1 * seed)
            den2 = Item(gen2 * seed)

            temp1 = randomly.integer(1, 20)
            temp2 = randomly.integer(1, 20)

            num1 = Item(temp1 // gcd(temp1, gen1 * seed))
            num2 = Item(temp2 // gcd(temp2, gen2 * seed))

            f1 = Fraction((randomly.sign(plus_signs_ratio=0.7), num1, den1))
            f2 = Fraction((randomly.sign(plus_signs_ratio=0.7), num2, den2))

            self.objct = Sum([f1.simplified(), f2.simplified()])

        # 5th
        # still to imagine:o)

        # Creation of the expression:
        number = 0
        if 'expression_number' in options                                     \
           and is_.a_natural_int(options['expression_number']):
            # __
            number = options['expression_number']
        self.expression = Expression(number, self.objct)
Esempio n. 3
0
def level_01(q_subkind, **options):
    if q_subkind == 'default' \
       or q_subkind == 'three_terms' \
       or q_subkind == 'ax + b' \
       or q_subkind == 'ax² + b' \
       or q_subkind == 'ax² + bx':
        # __
        # the idea is to build the final factorized result first and to
        # expand it to get the question (and the solution's steps
        # in the same time)

        if q_subkind == 'default':
            common_factor = Monomial((RANDOMLY, 6, 1))
            # In order to reduce the number of cases where x² appears,
            # let the common factor be of degree 0 most of the time.
            common_factor.set_degree(
                randomly.integer(0, 1, weighted_table=[0.85, 0.15]))
        elif q_subkind in ['three_terms', 'ax + b', 'ax² + b']:
            common_factor = Monomial((RANDOMLY, 6, 0))

        elif q_subkind == 'ax² + bx':
            common_factor = Monomial((RANDOMLY, 6, 1))
            common_factor.set_degree(1)

        # to avoid having a situation like 1×(2x + 3) which isn't
        # factorizable:
        if common_factor.get_degree() == 0:
            common_factor.set_coeff(randomly.integer(2, 6))

        # signs are randomly chosen ; the only case that is to be avoided
        # is all signs are negative (then it wouldn't factorize well...
        # I mean then the '-' should be factorized and not left in the final
        # result)
        signs_box = [['+', '+'], ['+', '-']]
        signs = randomly.pop(signs_box)

        # this next test is to avoid -2x + 6 being factorized -2(x - 3)
        # which is not wrong but not "natural" to pupils
        # this test should be changed when a third term is being used.
        if signs == ['+', '-']:
            common_factor.set_sign('+')

        coeff_1 = randomly.integer(2, 10)
        coeff_2 = randomly.coprime_to(coeff_1, [i + 1 for i in range(10)])
        coeff_3 = None

        if q_subkind == 'three_terms':
            coeff_3 = randomly.coprime_to(coeff_1 * coeff_2,
                                          [i + 1 for i in range(9)])
            third_sign = randomly.sign()
            if third_sign == '-':
                common_factor.set_sign('+')

            signs.append(third_sign)

        lil_box = []
        lil_box.append(Monomial(('+', 1, 0)))

        if q_subkind == 'ax² + b':
            lil_box.append(Monomial(('+', 1, 2)))
        else:
            lil_box.append(Monomial(('+', 1, 1)))

        if ((common_factor.get_degree() == 0 and randomly.integer(1, 20) > 17
             and q_subkind == 'default') or q_subkind == 'three_terms'):
            # __
            lil_box.append(Monomial(('+', 1, 2)))

        first_term = randomly.pop(lil_box)
        second_term = randomly.pop(lil_box)
        third_term = None

        first_term.set_coeff(coeff_1)
        first_term.set_sign(randomly.pop(signs))
        second_term.set_coeff(coeff_2)
        second_term.set_sign(randomly.pop(signs))

        if q_subkind == 'three_terms':
            third_term = randomly.pop(lil_box)
            third_term.set_coeff(coeff_3)
            third_term.set_sign(randomly.pop(signs))
            if first_term.is_positive() and second_term.is_positive()\
               and third_term.is_positive():
                # __
                common_factor.set_sign(randomly.sign())

        if not (q_subkind == 'three_terms'):
            if common_factor.get_degree() == 0 \
               and first_term.get_degree() >= 1 \
               and second_term.get_degree() >= 1:
                # __
                if randomly.heads_or_tails():
                    first_term.set_degree(0)
                else:
                    second_term.set_degree(0)

        if q_subkind == 'three_terms':
            solution = Expandable(
                (common_factor, Sum([first_term, second_term, third_term])))

        else:
            solution = Expandable(
                (common_factor, Sum([first_term, second_term])))

        # now create the expanded step and the reduced step (which will
        # be given as a question)
        temp_steps = []
        current_step = solution.clone()

        while current_step is not None:
            temp_steps.append(current_step)
            current_step = current_step.expand_and_reduce_next_step()

        # now we put the steps in the right order
        steps = []
        for i in range(len(temp_steps)):
            steps.append(temp_steps[len(temp_steps) - 1 - i])

        return steps

    elif q_subkind == 'not_factorizable':
        signs_box = [['+', '+'], ['+', '-']]
        signs = randomly.pop(signs_box)

        coeff_1 = randomly.integer(2, 10)
        coeff_2 = randomly.coprime_to(coeff_1, [i + 1 for i in range(10)])

        lil_box = []
        lil_box.append(Monomial(('+', 1, 0)))
        lil_box.append(Monomial(('+', 1, 1)))
        lil_box.append(Monomial(('+', 1, 2)))

        first_term = randomly.pop(lil_box)
        second_term = randomly.pop(lil_box)

        first_term.set_coeff(coeff_1)
        first_term.set_sign(randomly.pop(signs))

        second_term.set_coeff(coeff_2)
        second_term.set_sign(randomly.pop(signs))

        if first_term.get_degree() >= 1 \
           and second_term.get_degree() >= 1:
            # __
            if randomly.heads_or_tails():
                first_term.set_degree(0)
            else:
                second_term.set_degree(0)

        steps = []
        solution = _("So far, we don't know if this expression can be "
                     "factorized.")
        steps.append(Sum([first_term, second_term]))
        steps.append(solution)

        return steps
Esempio n. 4
0
def level_02(q_subkind, **options):

    max_coeff = 20

    if 'max_coeff' in options and is_.an_integer(options['max_coeff']):
        max_coeff = options['max_coeff']

    attribute_a_minus_sign = 'randomly'

    if 'minus_sign' in options and options['minus_sign']:
        attribute_a_minus_sign = 'yes'

    elif 'minus_sign' in options and not options['minus_sign']:
        attribute_a_minus_sign = 'no'

    # Creation of the objects

    # The three Monomials: ax², bx and c
    # Maybe we don't need to keep the integer values...
    a_val = randomly.integer(1, max_coeff)
    b_val = randomly.integer(1, max_coeff)
    c_val = randomly.integer(1, max_coeff)

    if q_subkind in [
            'type_1_A0', 'type_1_B0', 'type_1_C0', 'type_1_A1', 'type_1_B1',
            'type_1_C1'
    ]:
        # __
        c_val = randomly.integer(2, max_coeff)

    ax2 = Monomial((randomly.sign(), a_val, 2))
    bx = Monomial((randomly.sign(), b_val, 1))
    c = Monomial((randomly.sign(), c_val, 0))

    # deg1: mx + p
    # and we need two of them
    deg1 = []
    for i in range(2):
        deg1_mx = Monomial((randomly.sign(), randomly.integer(1,
                                                              max_coeff), 1))
        deg1_p = None

        if q_subkind in [
                'type_1_A0', 'type_1_B0', 'type_1_C0', 'type_1_D0',
                'type_1_E0', 'type_1_F0', 'type_1_G0', 'type_1_H0',
                'type_1_I0', 'type_1_A1', 'type_1_B1', 'type_1_D1',
                'type_1_E1', 'type_1_G1', 'type_1_H1', 'type_4_A0'
        ]:
            # __
            deg1_p = Monomial(
                (randomly.sign(), randomly.integer(1, max_coeff), 0))
        else:
            deg1_p = Monomial(
                (randomly.sign(), randomly.integer(0, max_coeff), 0))

        if not deg1_p.is_null():
            lil_box = [deg1_mx, deg1_p]
            deg1.append(
                Polynomial([randomly.pop(lil_box),
                            randomly.pop(lil_box)]))

        else:
            deg1.append(deg1_mx)

    # deg2: mx² + px + r
    # and we also need two of them
    deg2 = []
    for i in range(2):
        deg2_mx2 = Monomial((randomly.sign(), randomly.integer(1,
                                                               max_coeff), 2))

        deg2_px = None
        deg2_r = None

        if q_subkind in [
                'type_1_A0', 'type_1_B0', 'type_1_C0', 'type_1_D0',
                'type_1_E0', 'type_1_F0', 'type_1_G0', 'type_1_H0',
                'type_1_I0', 'type_1_A1', 'type_1_B1', 'type_1_D1',
                'type_1_E1', 'type_1_G1', 'type_1_H1'
        ]:
            # __
            if randomly.heads_or_tails():
                deg2_px = Monomial(
                    (randomly.sign(), randomly.integer(1, max_coeff), 1))
                deg2_r = Monomial(
                    (randomly.sign(), randomly.integer(0, max_coeff), 0))
            else:
                deg2_px = Monomial(
                    (randomly.sign(), randomly.integer(0, max_coeff), 1))
                deg2_r = Monomial(
                    (randomly.sign(), randomly.integer(1, max_coeff), 0))
        else:
            deg2_px = Monomial(
                (randomly.sign(), randomly.integer(0, max_coeff), 1))
            deg2_r = Monomial(
                (randomly.sign(), randomly.integer(0, max_coeff), 0))

        lil_box = [deg2_mx2]

        if not deg2_px.is_null():
            lil_box.append(deg2_px)
        if not deg2_r.is_null():
            lil_box.append(deg2_r)

        monomials_list_for_deg2 = []
        for i in range(len(lil_box)):
            monomials_list_for_deg2.append(randomly.pop(lil_box))

        deg2.append(Polynomial(monomials_list_for_deg2))

    # Let's attribute the common factor C according to the required type
    # (NB: expression ± C×F1 ± C×F2)
    C = None

    if q_subkind in [
            'type_1_A0', 'type_1_B0', 'type_1_C0', 'type_1_A1', 'type_1_B1'
    ]:
        # __
        C = c

    elif q_subkind in [
            'type_1_D0', 'type_1_E0', 'type_1_F0', 'type_1_D1', 'type_1_E1'
    ]:
        # __
        C = bx

    elif q_subkind in [
            'type_1_G0', 'type_1_H0', 'type_1_I0', 'type_1_G1', 'type_1_H1'
    ]:
        # __
        C = ax2

    elif q_subkind in [
            'type_2_A0', 'type_2_B0', 'type_2_C0', 'type_2_A1', 'type_2_B1',
            'type_4_A0'
    ]:
        # __
        C = Polynomial([bx, c])

    elif q_subkind in [
            'type_2_D0', 'type_2_E0', 'type_2_F0', 'type_2_D1', 'type_2_E1'
    ]:
        # __
        C = Polynomial([ax2, c])

    elif q_subkind in [
            'type_3_A0', 'type_3_B0', 'type_3_C0', 'type_3_A1', 'type_3_B1'
    ]:
        # __
        C = Polynomial([ax2, bx, c])

    # Let's attribute F1 and F2 according to the required type
    # (NB: expression ± C×F1 ± C×F2)
    F1 = None
    F2 = None

    if q_subkind in [
            'type_1_A0', 'type_1_A1', 'type_1_D0', 'type_1_D1', 'type_1_G0',
            'type_1_G1', 'type_2_A0', 'type_2_A1', 'type_2_D0', 'type_2_D1',
            'type_3_A0', 'type_3_A1'
    ]:
        # __
        F1 = deg1[0]
        F2 = deg1[1]

    elif q_subkind in [
            'type_1_B0', 'type_1_B1', 'type_1_E0', 'type_1_E1', 'type_1_H0',
            'type_1_H1', 'type_2_B0', 'type_2_B1', 'type_2_E0', 'type_2_E1',
            'type_3_B0', 'type_3_B1'
    ]:
        # __
        F1 = deg2[0]
        F2 = deg2[1]

    elif q_subkind in [
            'type_1_C0', 'type_1_F0', 'type_1_I0', 'type_2_C0', 'type_2_F0',
            'type_3_C0'
    ]:
        # __
        F1 = deg1[0]
        F2 = deg2[0]

    # The special case type_4_A0: (ax+b)² + (ax+b)×deg1'
    #                       aka    C² + C×F1
    elif q_subkind == 'type_4_A0':
        F1 = C.clone()
        F2 = deg1[0]

    # Let's put a "1" somewhere in the type_*_*1
    if q_subkind in [
            'type_1_A1', 'type_1_D1', 'type_1_G1', 'type_2_A1', 'type_2_D1',
            'type_3_A1', 'type_1_B1', 'type_1_E1'
            'type_1_H1', 'type_2_B1', 'type_2_E1', 'type_3_B1'
    ]:
        # __
        if randomly.heads_or_tails():
            F1 = Item(1)
        else:
            F2 = Item(1)

    # Let's possibly attribute a minus_sign
    # (NB: expression ± C×F1 ± C×F2)
    minus_sign = None
    # this will contain the name of the factor having
    # a supplementary minus sign in such cases:
    # C×F1 - C×F2# - C×F1 + C×F2

    # in all the following cases, it doesn't bring anything to attribute
    # a minus sign
    if ((q_subkind
         in ['type_1_A0', 'type_1_B0', 'type_1_C0', 'type_1_A1', 'type_1_B1']
         and c_val < 0) or
        ((q_subkind
          in ['type_1_D0', 'type_1_E0', 'type_1_F0', 'type_1_D1', 'type_1_E1'])
         and b_val < 0) or
        ((q_subkind
          in ['type_1_G0', 'type_1_H0', 'type_1_I0', 'type_1_G1', 'type_1_H1'])
         and a_val < 0)):
        # __
        pass  # here we let minus_sign equal to None

    # otherwise, let's attribute one randomly,
    # depending on attribute_a_minus_sign
    else:
        if attribute_a_minus_sign in ['yes', 'randomly']:
            # __
            if (attribute_a_minus_sign == 'yes' or randomly.heads_or_tails()):
                # __
                if randomly.heads_or_tails():
                    minus_sign = "F1"
                else:
                    minus_sign = "F2"
            else:
                pass  # here we let minus_sign equal to None

    # Now let's build the expression !
    expression = None
    box_product1 = [C, F1]
    box_product2 = [C, F2]

    if q_subkind == 'type_4_A0':
        CF1 = Product([C])
        CF1.set_exponent(Value(2))
    else:
        CF1 = Product([randomly.pop(box_product1), randomly.pop(box_product1)])

    CF2 = Product([randomly.pop(box_product2), randomly.pop(box_product2)])

    if minus_sign == "F1":
        if len(F1) >= 2:
            CF1 = Expandable((Item(-1), CF1))
        else:
            CF1 = Product([Item(-1), CF1])

    elif minus_sign == "F2":
        if len(F2) >= 2:
            CF2 = Expandable((Item(-1), CF2))
        else:
            CF2 = Product([Item(-1), CF2])

    expression = Sum([CF1, CF2])

    # Now let's build the factorization steps !
    steps = []
    steps.append(expression)

    F1F2_sum = None

    if minus_sign is None:
        F1F2_sum = Sum([F1, F2])

    elif minus_sign == "F1":
        if len(F1) >= 2:
            F1F2_sum = Sum([Expandable((Item(-1), F1)), F2])
        else:
            F1F2_sum = Sum([Product([Item(-1), F1]), F2])

    elif minus_sign == "F2":
        if len(F2) >= 2:
            F1F2_sum = Sum([F1, Expandable((Item(-1), F2))])
        else:
            F1F2_sum = Sum([F1, Product([Item(-1), F2])])

    temp = Product([C, F1F2_sum])
    temp.set_compact_display(False)
    steps.append(temp)

    F1F2_sum = F1F2_sum.expand_and_reduce_next_step()

    while F1F2_sum is not None:
        steps.append(Product([C, F1F2_sum]))
        F1F2_sum = F1F2_sum.expand_and_reduce_next_step()

    # This doesn't fit the need, because too much Products are
    # wrongly recognized as reducible !
    if steps[len(steps) - 1].is_reducible():
        steps.append(steps[len(steps) - 1].reduce_())

    return steps
    def __init__(self, q_kind='default_nothing', **options):
        self.derived = True

        # The call to the mother class __init__() method will set the
        # fields matching optional arguments which are so far:
        # self.q_kind, self.q_subkind
        # plus self.options (modified)
        Q_Structure.__init__(self, q_kind, AVAILABLE_Q_KIND_VALUES, **options)
        # The purpose of this next line is to get the possibly modified
        # value of **options
        options = self.options

        MAX_COEFF = MAX_COEFF_TABLE[q_kind]
        MAX_EXPONENT = MAX_EXPONENT_TABLE[q_kind]
        DEFAULT_MINIMUM_LENGTH = DEFAULT_MINIMUM_LENGTH_TABLE[q_kind]
        DEFAULT_MAXIMUM_LENGTH = DEFAULT_MAXIMUM_LENGTH_TABLE[q_kind]

        # This field is to be used in the answer_to_strs() method
        # to determine a possibly different algorithm for particular cases
        self.kind_of_answer = ""

        # Max coefficient & degree values...
        max_coeff = MAX_COEFF
        max_expon = MAX_EXPONENT

        if 'max_coeff' in options and options['max_coeff'] >= 1:
            max_coeff = options['max_coeff']

        if 'max_expon' in options and options['max_expon'] >= 1:
            max_expon = options['max_expon']

        length = randomly.integer(DEFAULT_MINIMUM_LENGTH,
                                  DEFAULT_MAXIMUM_LENGTH,
                                  weighted_table=[0.15, 0.25, 0.6])

        if ('length' in options and is_.an_integer(options['length'])
                and options['length'] >= 2):
            # __
            length = options['length']

        # 1st CASE:
        # PRODUCT REDUCTION
        if q_kind == 'product':
            # First let's determine a pack of letters where to draw
            # The default one will be [a, b, c, x, y, z]
            # but the reduced or entire alphabets can be used as well
            letters_package = alphabet.abc + alphabet.xyz

            if 'short_test' in options and options['short_test']:
                # __
                self.objct = Product(
                    [Monomial((RANDOMLY, 12, 1)),
                     Monomial((RANDOMLY, 12, 1))])

                self.objct.factor[0].set_degree(1)
                self.objct.factor[1].set_degree(1)

            else:
                # In the case of an exercise about reducing products
                # in a training sheet, the answers will be more detailed
                self.kind_of_answer = 'product_detailed'
                if 'use_reduced_alphabet' in options:
                    letters_package = alphabet.reduced

                elif 'use_the_entire_alphabet' in options:
                    letters_package = alphabet.lowercase

                elif 'use_these_letters' in options                           \
                     and is_.a_string_list(options['use_these_letters']):
                    # __
                    letters_package = options['use_these_letters']

                # Maximum Items number. (We make sure at the same time that
                # we won't
                # risk to draw a greater number of letters than the available
                # letters
                # in letters_package)
                max_literal_items_nb = min(PR_MAX_LITERAL_ITEMS_NB,
                                           len(letters_package))

                if ('max_literal_items_nb' in options
                        and 2 <= options['max_literal_items_nb'] <= 6):
                    # __
                    max_literal_items_nb = min(options['max_literal_items_nb'],
                                               len(letters_package))

                # Maximum number of occurences of the same letter in
                # the initial expression
                same_letter_max_occurences = PR_SAME_LETTER_MAX_OCCURENCES_NB

                if ('nb_occurences_of_the_same_letter' in options
                        and options['nb_occurences_of_the_same_letter'] >= 1):
                    # __
                    same_letter_max_occurences = options['nb_occurences_of'
                                                         '_the_same_letter']

                # CREATION OF THE EXPRESSION
                # We draw randomly the letters that will appear
                # in the expression
                current_letters_package = list(letters_package)

                nb_of_letters_to_draw = randomly.integer(
                    1, max_literal_items_nb)

                drawn_letters = list()

                for j in range(nb_of_letters_to_draw):
                    drawn_letters.append(randomly.pop(current_letters_package))

                # Let's determine how many times will appear each letter
                # and then create a list containing each of these letters
                # the number of times they will appear
                pre_items_list = list()
                items_list = list()

                for j in range(len(drawn_letters)):
                    if j == 0:
                        # We make sure that at least one letter occurs twice
                        # so that the exercise remains interesting !
                        # But the number of cases this letter occurs 3 three
                        # times  should be limited to keep sufficient
                        # simple cases for the pupils to begin with.
                        # It is really easy to make it much more complicated
                        # simply giving:
                        # nb_occurences_of_the_same_letter=<enough_high_nb>
                        # as an argument.
                        if randomly.decimal_0_1() < 0.5:
                            occurences_nb = 2
                        else:
                            occurences_nb = randomly\
                                .integer(2, same_letter_max_occurences)
                    else:
                        occurences_nb = randomly\
                            .integer(1, same_letter_max_occurences)

                    if occurences_nb >= 1:
                        for k in range(occurences_nb):
                            pre_items_list.append(drawn_letters[j])

                # draw the number of numeric Items
                nb_item_num = randomly.integer(1, PR_NUMERIC_ITEMS_MAX_NB)

                # put them in the pre items' list
                for j in range(nb_item_num):
                    pre_items_list.append(NUMERIC)

                # prepare the items' list that will be given to the Product's
                # constructor
                loop_nb = len(pre_items_list)

                for j in range(loop_nb):
                    next_item_kind = randomly.pop(pre_items_list)

                    # It's not really useful nor really possible to limit the
                    # number
                    # of occurences of the same letter being drawn twice in
                    # a row because it belongs to the exercise and there
                    # are many cases when
                    # the same letter is in the list in 3 over 4 elements.
                    # if j >= 1 and next_item_kind == items_list[j - 1]
                    # .raw_value:
                    #    pre_items_list.append(next_item_kind)
                    #    next_item_kind = randomly.pop(pre_items_list)

                    if next_item_kind == NUMERIC:
                        temp_item = Item((randomly.sign(plus_signs_ratio=0.75),
                                          randomly.integer(1, max_coeff), 1))
                        items_list.append(temp_item)

                    else:
                        item_value = next_item_kind
                        temp_item = Item(
                            (randomly.sign(plus_signs_ratio=0.9), item_value,
                             randomly.integer(1, max_expon)))
                        items_list.append(temp_item)

                # so now that the items_list is complete,
                # let's build the Product !
                self.objct = Product(items_list)
                self.objct.set_compact_display(False)

                # Let's take some × symbols off the Product to match a more
                # usual situation
                for i in range(len(self.objct) - 1):
                    if ((self.objct.factor[i].is_numeric()
                         and self.objct.factor[i + 1].is_literal())
                            or (self.objct.factor[i].is_literal()
                                and self.objct.factor[i + 1].is_literal()
                                and self.objct.factor[i].raw_value !=
                                self.objct.factor[i + 1].raw_value
                                and randomly.decimal_0_1() > 0.5)):
                        # __
                        self.objct.info[i] = False

        # 2d CASE:
        # SUM OF PRODUCTS REDUCTION
        if q_kind == 'sum_of_products':
            if (not ('length' in options and is_.an_integer(options['length'])
                     and options['length'] >= 2)):
                # __
                length = randomly.integer(DEFAULT_MINIMUM_LENGTH,
                                          DEFAULT_MAXIMUM_LENGTH,
                                          weighted_table=[0.15, 0.25, 0.6])

            # Creation of the list to give later to the Sum constructor
            products_list = list()

            for i in range(length):
                monomial1 = Monomial((RANDOMLY, max_coeff, max_expon))
                monomial2 = Monomial((RANDOMLY, max_coeff, max_expon))
                products_list.append(Product([monomial1, monomial2]))

            # Creation of the Sum
            self.objct = Sum(products_list)

        # 3d CASE:
        # SUM REDUCTION
        if q_kind == 'sum':
            self.kind_of_answer = 'sum'
            # Let's determine the length of the Sum to create
            if not ('length' in options and is_.an_integer(options['length'])
                    and options['length'] >= 1):
                # __
                length = randomly\
                    .integer(DEFAULT_MINIMUM_LENGTH,
                             DEFAULT_MAXIMUM_LENGTH,
                             weighted_table=[0.1, 0.25, 0.5, 0.1, 0.05])

            else:
                length = options['length']

            # Creation of the Polynomial...

            if 'short_test' in options:
                self.objct = Polynomial((RANDOMLY, max_coeff, 2, length - 1))
                temp_sum = self.objct.term

                degree_1_monomial_here = False
                for i in range(len(temp_sum)):
                    if temp_sum[i].degree == 1:
                        degree_1_monomial_here = True

                if degree_1_monomial_here == 1:
                    temp_sum.append(Monomial((randomly.sign(), 1, 1)))
                else:
                    # this should be 2d deg Polynomial w/out any 1st deg term
                    temp_sum.append(Monomial((randomly.sign(), 1, 2)))

                self.objct.reset_element()

                for i in range(length):
                    self.objct.term.append(randomly.pop(temp_sum))
                    self.objct.info.append(False)

            else:
                self.objct = Polynomial(
                    (RANDOMLY, max_coeff, max_expon, length))

        if q_kind == 'long_sum':
            m = []

            for i in range(length):
                m.append(Monomial(RANDOMLY, max_coeff, max_expon))

            self.objct = Polynomial(m)

        if q_kind == 'long_sum_including_a_coeff_1':
            m = []

            for i in range(length - 1):
                m.append(Monomial(RANDOMLY, max_coeff, max_expon))

            m.append(Monomial(RANDOMLY, 1, max_expon))

            terms_list = []

            for i in range(len(m)):
                terms_list.append(randomly.pop(m))

            self.objct = Polynomial(terms_list)

        if q_kind == 'sum_not_reducible':
            self.kind_of_answer = 'sum_not_reducible'

            m1 = Monomial((RANDOMLY, max_coeff, 0))
            m2 = Monomial((RANDOMLY, max_coeff, 1))
            m3 = Monomial((RANDOMLY, max_coeff, 2))

            lil_box = [m1, m2, m3]

            self.objct = Polynomial([randomly.pop(lil_box)])

            for i in range(len(lil_box) - 1):
                self.objct.append(randomly.pop(lil_box))

        if q_kind == 'sum_with_minus-brackets':
            minus_brackets = []

            for i in range(3):
                minus_brackets.append(
                    Expandable((Monomial(('-', 1, 0)),
                                Polynomial(
                                    (RANDOMLY, 15, 2, randomly.integer(2,
                                                                       3))))))
            m1 = Monomial((RANDOMLY, max_coeff, 0))
            m2 = Monomial((RANDOMLY, max_coeff, 1))
            m3 = Monomial((RANDOMLY, max_coeff, 2))
            m4 = Monomial((RANDOMLY, max_coeff, randomly.integer(0, 2)))

            lil_box = [m1, m2, m3, m4]

            plus_brackets = []

            for i in range(3):
                plus_brackets.append(
                    Expandable((Monomial(('+', 1, 0)),
                                Polynomial(
                                    (RANDOMLY, 15, 2, randomly.integer(2,
                                                                       3))))))

            big_box = []
            big_box.append(minus_brackets[0])

            if ('minus_brackets_nb' in options
                    and 2 <= options['minus_brackets_nb'] <= 3):
                # __
                big_box.append(minus_brackets[1])

                if options['minus_brackets_nb'] == 3:
                    big_box.append(minus_brackets[2])

            for i in range(randomly.integer(1, 4)):
                big_box.append(randomly.pop(lil_box))

            if ('plus_brackets_nb' in options
                    and 1 <= options['plus_brackets_nb'] <= 3):
                # __
                for i in range(options['plus_brackets_nb']):
                    big_box.append(plus_brackets[i])

            final_terms = []

            for i in range(len(big_box)):
                final_terms.append(randomly.pop(big_box))

            self.objct = Sum(final_terms)

        # Creation of the expression:
        number = 0
        if ('expression_number' in options
                and is_.a_natural_int(options['expression_number'])):
            # __
            number = options['expression_number']

        self.expression = Expression(number, self.objct)