Less-than sign been repurposed for a range of uses and operations. The less-than sign (<) is an original ASCII character (hex 3C, decimal 60). The less-than sign is used for an approximation of the opening angle bracket (⟨). ASCII does not have angle brackets. In BASIC, Lisp-family languages, and C-family languages (including Java and C++), operator < means "less than". In Coldfusion, operator .lt. means "less than". In Fortran, operator .LT. means "less than"; later versions allow <. In Bourne shell, operator -lt means "less than". The double less-than sign («) is used for an approximation of the much-less-than sign (≪) or
Degrees of freedom (statistics) vector (made up of "n" − 1 degrees of freedom within each of the populations). In statistical testing problems, one usually isn't interested in the component vectors themselves, but rather in their squared lengths, or Sum of Squares. The degrees of freedom associated with a sum-of-squares is the degrees-of-freedom of the corresponding component vectors. The three-population example above is an example of one-way Analysis of Variance. The model, or treatment, sum-of-squares is the squared length of the second vector, with 2 degrees of freedom. The residual, or error, sum-of-squares is with 3("n"−1) degrees of freedom. Of course, introductory books on