A Stamp Collector Wants to Include in Her Collection Exactly $I$

A stamp collector wants to include in her collection exactly one stamp from each country of Africa. If $I$ (s) means that she has stamp $s$ in her collection, $F ( s , c )$ means that stamp $s$ was issued by country $c$ , the domain for $s$ is all stamps, and the domain for $c$ is all countries of Africa, express the statement that her collection satisfies her requirement. Do not use the $\exists$ ! symbol.