put shortcircuit to avoid allclose

[cacodcar]

I ran a profile using one of Harsh's case study, and numpy.allclose (in detect_implicit_equalities) is the most time consuming part of the solution procedure

Hence, added some short circuits

1. if looking at same block: only check two will be possible, so continue without running any checks
2. if after check two, neither checks have yielded, check three is unnecessary as the checks > 2 is not possible
3. Conversely, if both check 1 and check 2 have already yielded... computationally expensive check three can be skipped