sequence function: test-input-seq

    description:
        test-input-seq(input-seq, seq, seq)
        our first and only sequence function that makes use of input-seq
        all it does is print out the given sequences, and return input-seq
        just a place-holder until we find a real application of input-seq feature
    
    examples:
        test-input-seq(|a>, |b>) (|x> . |y>)
            input_seq: |x> . |y>
            one: |a>
            two: |b>
            |x> . |y>
        
    see also: