This example is defined in the directory: /home/lbesnard/Polychrony/V4.19/Linux/Examples/mouse/Static_property.
This directory contains the description in Signal of a mouse handler, which is a control example. This program is similar to the mouse program, in which the definition of a signal, necessary to prove a static property on the program, has been added.
(we do not describe systematically all the files related to this version of the mouse program; these files contain "_P1" in their name)
VTMOUSE_P1.gpk is the same program as VTMOUSE.gpk, in which the definition of the signal INTER has been added. This signal is defined as follows: INTER := START when RELAX
To prove that START and RELAX are exclusive signals, it is sufficient to show that the signal INTER is never defined, i.e., its clock is the null clock .
This is done by the compiler:
# WARNING : program with null clock signals
^0 ^= INTER***war: null clock signals
So the property is proved.