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
Six degrees of freedom the configuration of the manipulator defined by its forward and inverse kinematics. Robot arms are described by their degrees of freedom. This number typically refers to the number of single-axis rotational joints in the arm, where higher number indicates an increased flexibility in positioning a tool. This is a practical metric, in contrast to the abstract definition of degrees of freedom which measures the aggregate positioning capability of a system. In 2007, Dean Kamen, inventor of the Segway, unveiled a prototype robotic arm with 14 degrees of freedom for DARPA. Humanoid robots typically have 30 or more degrees of freedom,