Semistable genus 5 general type P�-curves have at least 7 singular fibres

We prove that if f : X -> P� is a non-isotrivial, semistable, genus 5 fibration defined on a general type surface X then the number s of singular fibres is at least 7我们证明，若映射$f: X omathbb{P}^1$为定义于一般型曲面$X$上的非等平凡半稳定亏格5纤维化，则其奇异纤维的数量$s$至少为7。