sequence function: simm

    description:
        simm(seq, seq)
        simm(seq, seq) input-ket
        the aligned sequences version of our similarity measure
        for each superposition in our sequences, calculate the similarity measure
        (ie, 0 for completely distinct, 1 for exactly the same, values in between otherwise)
        then average them
            
    examples:
        simm(|a>, |b>)
            0|simm>
        
        simm(3|a> + 1.2|b>, 3.5|a> + 0.9|b> + 5.13|c>)
            0.462|simm>        

        simm(|a1> + |a2> . 0.3|b1> + 0.5|b2>, 3|a1> + 0.9|a2> . 0.7|b2>)
            0.678|simm>        

        rename-simm |simm> => |result>
        push-float rename-simm simm(|a>, split |a b c d>)
            |result: 0.25>
            
        -- now using input-ket we can do the same using:
        push-float simm(|a>, split |a b c d>) |result>
            |result: 0.25>
            
    see also:
        unscaled-simm