A Type of Hyperelliptic Continued Fraction

Based on hints of Tschebychev, a continued fraction is described which gives an effective algorithm for calculating the torsion, if finite, of divisors D − D⁻ on a hyperelliptic curve of genus ≥2, where D is an effective divisor of degree 2 and D⁻ denotes the image of D under the hyperelliptic involution. The difficulties involved in extending the algorithm to divisors of degree ≥3 are briefly discussed.