hyperstudy调用函数出错？ 20

按照help文件建立了.hml文件，和.mvw文件，调用函数建立响应，evaluate expression时错误提示如下:按照help文件捋了一遍还是没找到错误，各位老师受累帮助看一下是哪里出错？ 15 Error : Cannot evaluate expression ( area_between_two_curves(v_1,v_3,v_2,v_4) ), ...trator/Desktop/HEMI-MATH/area_between_two_curves.hml:3: 'sync2' is uninitialized stack traceback: [C]: ? ...trator/Desktop/HEMI-MATH/area_between_two_curves.hml:3: in function [C]: ? Check if all expressions, preference files, sources and other components are valid.