Math question. What is this operation called?

Computer scientis write it like this

Cracked by: Goyal , Achilles , nihit , Keerthi M R , Phani , Dibyo , varuns88 , shenoyvarun86 , akhi , madhur , sidsen , Ananth , udupendra and mandakhawke.

Goyal, Achilles, nihit, Keerthi M R, Phani, Dibyo, varuns88, shenoyvarun86, akhi, madhur, sidsen, Ananth, udupendra and mandakhawke