minusXsYpredminusXYminusX0XpredsXXlesXsYleXYlesX0falsele0Ytruegcd0Y0gcdsX0sXgcdsXsYifleYXsXsYiftruesXsYgcdminusXYsYiffalsesXsYgcdminusYXsXminus2s1pred100le2false0true0gcd2if3INNERMOST./TRS/Rubio/gcd.trs