J. Black. 2002. A Dictionary of economics. Oxford Univ. Press
"Improvement in knowledge of possible techniques. Such changes may allow more output to be obtained from unchanged inputs, the same output to be obtained from fewer inputs, or new forms of output to be produced which were not previously possible"
(1) More output with same inputs
(2) Smae output with fewer inputs
(3) New output(pure innovation?), eventually more output
Except (3), is the basic of technical progress substitution? Through substitution or reorganization of production process, we can produce more or the same with fewer inputs.