Mathematical Structures: History of Categories

# History of Categories

 The set of objects of $C$ is the set $\mathbf{Obj}C=\{\text{dom}(x)|x\in C\}. For$a,b\in C$the set of homomorphism from$a$to$b$is  The set of objects of$C$is the set$\mathbf{Obj}C=\{\text{dom}(x)|x\in C\}$. For$a,b\in C$the set of homomorphism from$a$to$b\$ is