`type name = string`
`type version = string`
`type architecture = string`
`type architectures = architecture list`
`type buildprofile = string`
`type vpkgname = string * architecture option`
`type multiarch = [`

1. `| `Foreign`
2. `| `Allowed`
3. `| `No`
4. `| `Same`

`]`
`type source = name * version option`
`type relop = string`
`type constr = relop * version`
`type installed = bool`
`type vpkg = vpkgname * constr option`
`type vpkglist = vpkg list`
`type vpkgformula = vpkg list list`
`type builddep = vpkg * (bool * architecture) list * (bool * buildprofile) list list`
`type builddepslist = builddep list`
`type builddepsformula = builddep list list`
`type action =`

1. `| I`
2. `| R`

`type suite = string`
`type vpkgreq = action option * vpkg * suite option`