Add Ada 2012 function that breaks GNATprove with GNAT GPL 2012

Signed-off-by: David MENTRE <d.mentre@fr.merce.mee.com>
Add comment regarding Dimension_System available in GPL edition > 2012

Signed-off-by: David MENTRE <d.mentre@fr.merce.mee.com>
Start modelling §3.13.2. Add sec_3_13_test.adb to compile and test

* Add Time_t is Units package.

* Update project to compile sec_3_13_test.adb.

Signed-off-by: David MENTRE <d.mentre@fr.merce.mee.com>
Refactoring: rename Step_Function.Step_Function into Step_Function_t

* This avoid name clash with package Step_Function.

Signed-off-by: David MENTRE <d.mentre@fr.merce.mee.com>
More definitions related to Train related inputs

* Define a dummy body for the package

* Add new Decceleration_t type in Units

Signed-off-by: David MENTRE <d.mentre@fr.merce.mee.com>
More realistic values for Train inputs

Signed-off-by: David MENTRE <d.mentre@fr.merce.mee.com>
Add function Minimum_Until_Point with test and partial proof

Signed-off-by: David MENTRE <d.mentre@fr.merce.mee.com>