correct simple sample tests

Signed-off-by: Christoph Höger <christoph.hoeger@tu-berlin.de>
test flattening of time variable

Signed-off-by: Christoph Höger <christoph.hoeger@tu-berlin.de>
Add a simple relation test

Signed-off-by: Christoph Höger <christoph.hoeger@tu-berlin.de>
Add discrete value test

Signed-off-by: Christoph Höger <christoph.hoeger@tu-berlin.de>