def write_kr_titl_string(trs):
	"""
	write_kr_titl_string(trs)

	Write a title string for the list of lists of k-ratios and
	uncertainties output from the compKRs function.

	Input
	-----
	trs The transition set used to compute the K-ratios

	Return
	------
	A string with the title
	"""
	titl = "["
	for tr in trs:
		trName = tr.toString().split("-")[0]
		titl += "["
		titl += trName + ".mu," + trName + ".unc],"
	titl += "]"
	titl = titl.replace("],]", "]]")
	titl = titl.replace(" ", "")
	titl = titl.replace("All", "K") # for light element when all there is is K
	titl = titl.replace(",", ", ")  # add spaces in title at the end
	return(titl)