nominal hg38 = ()
nominal hg19 = ()
nominal chr1 = ()
nominal normalized = ()

union reference build =
    | Reference :: forall build. string -> reference build

union locus build contig =
    | Locus :: forall build contig. i32 -> locus build contig

union variant build contig state =
    | Variant :: forall build contig state. string -> variant build contig state

inl normalize forall build contig.
    (reference : reference build)
    (locus : locus build contig)
    : variant build contig normalized =
    match reference, locus with
    | Reference _, Locus _ => Variant "normalized-locus"

inl main () : string =
    inl reference : reference hg19 = Reference "hg19"
    inl locus : locus hg38 chr1 = Locus 101
    inl _ : variant hg38 chr1 normalized = normalize reference locus
    "unreachable"