is-less-than[value] ket returns yes/no if the value in ket < value
is-less-than[1000] |987> |yes> is-less-than[80] |age: 76> |yes> is-less-than[2000] |year: 2018> |no> -- if the ket has no float value then return the empty ket |> is-less-than[13] |the cat> |>