Example:Table as a function

From CS2800 wiki

Another way to draw a function is with a table:

x [math]f(x) [/math]
a 1
b 1
c 1

This almost describes a function; the domain is clearly [math]\{a,b,c\} [/math] (because if there were any other domain elements, [math]f [/math] would not be a function); and the rule is clear. However, the codomain is not clear: is it [math]\href{/cs2800/wiki/index.php/Enumerated_set}{\{1\}} [/math]? Or [math]\href{/cs2800/wiki/index.php/Enumerated_set}{\{1,2,3\}} [/math]? Or [math]\href{/cs2800/wiki/index.php/%E2%84%95}{ℕ} [/math], or [math]\href{/cs2800/wiki/index.php?title=%E2%84%9D&action=edit&redlink=1}{ℝ} [/math]? When describing a function with a table, the codomain should be specified somewhere.