Although the documentation makes them look variadic (and generic), they
are actually special-cased in the compiler. Like all built-in functions
they don't have a signature type, but the type of `min(a, b, c)` is
`func(int, int, int) int` and not `func(int, ...int) int`.

Go doesn't allow open-ended ranges for argument indices in
models-as-data specifications (though Ruby and Python do), so I've used
`1..1000`.