Is cereal a soup?
Let's discuss the great mysteries of the universe.
Tacos are love.
Of course a hot dog and a pizza are a sandwich. Sandwich is a generic term that progressively has grown to mean something a tid bit more specific image wise but none of the fundamentals of the definitions has been turned around in terms of usage. So getting down to precise coinage yes both of those examples are a sandwich. A "hot dog sandwich" is perfectly fine talking.
Quote:Tacos are love.
It's the friendly crunch which always gets me.
Tacos do not contain bread, therefore they are not sanmmiches.