D.J. Jeffrey and Robert M. Corless of the Ontario Research Centre for Computer Algebra at the University of Western Ontario wrote in their 2001 computer science paper on linear algebra instruction on the teaching concept. Jeffrey and Corless identified a "useful" lie-to-children, as one in which: "The pedagogical point is to avoid unnecessary burdens on the student’s first encounter with the concept." The authors gave an example from early childhood mathematics instruction: "We happily teach children that 'you cannot take 3 from 2' because we are confident that someone will later introduce them to negative numbers." Corless further expounded on this view in a subsequent paper published in 2004, writing: "A 'lie to children' is a useful oversimplification that starts one on the path to better knowledge. It is a truth unacknowledged that mathematics before computers was a lie to children."