cs$345$

Discrete structure $2$

$8\mathrm{.}20$ and $8\mathrm{.}21$ on page $400.$ For $8\mathrm{.}21,$ it would have helped if I provided a definition of R$^(-1)$ in the class notes to be the set where the ordered pairs of R are reversed. See for example page $393.($Even after one class period, I$\text{'}$m pretty much over trying to define a bunch of database relationships using mathematical notation.$)$

I am also gonna provise page $393$ example