在尝试构建包含的小型简单项目时出现以下错误在Xcode中:cmath:'*'hasnotbeendeclared'::acos'hasnotbeendeclaredInfileincludedfrom/Xcode4/Projects/libraryLAFMath/Classes/libraryLAFMath.cpInfileincludedfrom/Xcode4/Projects/libraryLAFMath/Classes/libraryLAFMath.h'::acos'hasnotbeendeclaredin/Xcode4/Platforms/iPhoneSimulator.pla