name of the relation

Take a topos $\mathcal{E}$ and a monic $\rho \colon R \hookrightarrow B \times A$ (thought of as a *relation* between $A$ and $B$). The *name* of $R$ is then the transpose $r \colon B \rightarrow \Omega^A$ of the characteristic map $\phi_{\rho} \colon B \times A \rightarrow \Omega$ of $\rho$ in $\mathcal{E}$.

**Peter Johnstone**, Sketches of an Elephant Section A2.1

Revised on February 27, 2014 20:22:56
by Anonymous Coward
(98.223.187.122)