> and tail are clearly concatted (is that a word?)[/color]
FWIW, and only since you asked: it's "concatenated".
concatenate /k<schwa>n"katIneIt/ v.t.
L16. [Late L concatenat- pa. ppl stem of concatenare, f. as
CON- + catena CHAIN n.: see -ATE3.]
Link together (chiefly fig.); connect as by a chain.