  We consider a macroscopic quantum system in a tilted double-well potential.
By solving Hamiltonian equation, we obtain tunneling probabilities which
contain oscillation effects. To show how one can decide between quantum
mechanics and the implications of macrorealism assumption, a given form of
Leggett-Garg inequality is used. The violation of this inequality occurs for a
broader range of decoherence effects, compared to previous results obtained for
two-level systems.
