Halmos on domain and range of relations
Posted by Paul , at math.stackexchange.com,
I am reading Halmos’s Naive Set Theory. He writes: If $R = X \times F$, then $\mbox{dom } R = X$ and $\mbox{ran } R = Y$. …
I am reading Halmos’s Naive Set Theory. He writes: If $R = X \times F$, then $\mbox{dom } R = X$ and $\mbox{ran } R = Y$. …
I am looking to expand my knowledge on set theory (which is pretty poor right now -- basic understanding of sets, power sets…