ket fn: print

        print ket
        print the given ket to standard out, appending a new line
        often used with the infix operators _ and __ which join ket labels, where __ inserts an extra space
        also frequently used with the smerge[] operator
        print returns the input ket, so it can be chained with other operators

        print |Just a short sentence.>
            Just a short sentence.
            |Just a short sentence.>
        print (|A> __ |short> __ |example> _ |.>)
            A short example.
            |A short example.>

        print smerge[", "] (|a> . |b> . |c>)
            a, b, c
            |a, b, c>

    see also:
        to-upper, to-lower, smerge