where·by 
/weɚˈbaɪ/ conjunction
/weɚˈbaɪ/ conjunction : by which : according to which
▪ They created a program whereby single parents could receive greater financial aid. [=a program that would allow single parents to receive greater financial aid]
▪ They created a program whereby single parents could receive greater financial aid. [=a program that would allow single parents to receive greater financial aid]
