context ket fn: starts-with

starts-with:
    description:
        starts-with |prefix>
        returns all known kets that starts-with the prefix "prefix"

    examples:
        -- eg, find people with a given first name:
        -- learn some people:
        first-name |Fred Smith> => |Fred>
        last-name |Fred Roberts> => |Roberts>
        middle-name |Sam J. Gleeson> => |Jack>
        age |Sam O'Conner> => |age: 47>
        mother |Sam Tompson> => |Liz Tompson>

        -- now find all kets that starts-with |Fred >
        starts-with |Fred >
            |Fred Smith> + |Fred Roberts>

        -- now find all kets that starts-with |Sam >
        starts-with |Sam >
            |Sam J. Gleeson> + |Sam O'Conner> + |Sam Tompson>

    see also:
        rel-kets