Initial morphism
Collection
context | $X:\mathrm{Ob}_{\bf C}$ |
context | $U$ in ${\bf D}\longrightarrow{\bf C}$ |
definiendum | $\langle A,\phi\rangle$ in $\mathrm{it}$ |
inclusion | $A:\mathrm{Ob}_{\bf D}$ |
inclusion | $\phi:{\bf C}[X,U(A)]$ |
for all | $B:\mathrm{Ob}_{\bf D}$ |
for all | $f:{\bf C}[X,U(B)]$ |
range | $g:{\bf D}[A,B]$ |
postulate | $\exists_!g.\ f=U(g)\circ\phi$ |
Discussion
For an elaboration, see terminal morphism, the dual concept.
Reference
Wikipedia: Universal property