let safeDiv num den : Choice<string, float> =
if den = 0. then
Choice1Of2 "divide by zero"
else
Choice2Of2 (num / den)
match safeDiv 15. 3. with
| Choice1Of2 msg -> printfn "%s" msg
| Choice2Of2 x -> printfn "%f" x
bGV0IHNhZmVEaXYgbnVtIGRlbiA6IENob2ljZTxzdHJpbmcsIGZsb2F0PiA9IAogICAgaWYgZGVuID0gMC4gdGhlbgogICAgICAgIENob2ljZTFPZjIgImRpdmlkZSBieSB6ZXJvIgogICAgZWxzZSAKICAgICAgICBDaG9pY2UyT2YyIChudW0gLyBkZW4pCgptYXRjaCBzYWZlRGl2IDE1LiAzLiB3aXRoCiAgICB8IENob2ljZTFPZjIgbXNnIC0+IHByaW50Zm4gIiVzIiBtc2cKICAgIHwgQ2hvaWNlMk9mMiB4IC0+IHByaW50Zm4gIiVmIiB4Cg==