Historically, the most important are the functions of the form 2 F 1 ( a , b ; c ; z ) {\displaystyle {}_{2}F_{1}(a,b;c;z)} .
Istoric vorbind, cele mai importante funcții au forma 2 F 1 ( a , b ; c ; z ) {\displaystyle \,_{2}F_{1}(a,b;c;z)} .