Due to a typo, the upper iteration uses `updateValueFromBelow` instead of `updateValueFromAbove`
to update the value vector. When the flag for monotonicity enforcement from above is active (default),
all values are thus forced to be above the upper bound, preventing convergence.
Example:
prism functionality/verify/mdps/reach/mdp_simple.nm functionality/verify/mdps/reach/mdp_simple.nm.props -sparse -intervaliter
+ test case
Joachim Klein