'The current decision level data structure
Examples
>>> from sympy.logic.algorithms.dpll2 import SATSolver
>>> l = SATSolver([{1}, {2}], {1, 2}, set())
>>> next(l._find_model())
{1: True, 2: True}
>>> l._current_level.decision
0
>>> l._current_level.flipped
False
>>> l._current_level.var_settings
{1, 2}'

@property
def _current_level(self):

    return self.levels[(-1)]
