T - homotopy and refinement of observation ( I ) : Introduction Philippe Gaucher

This paper is the extended introduction of a series of three papers [11] [9] [10] about modelling T-homotopy by refinement of observation. The notion of T-homotopy equivalence is discussed. A new one is proposed and its behaviour with respect to other constructions in dihomotopy theory is explained. We also prove in appendix that the tensor product of flows is a closed symmetric monoidal structure.