Function find_counterexample 

pub fn find_counterexample(
    init: &ProofExpr,
    trans: &dyn Fn(u32) -> ProofExpr,
    property: &dyn Fn(u32) -> ProofExpr,
    max_k: u32,
) -> BmcOutcome

Bounded model checking: search for a reachable state violating property within max_k transitions, returning the shallowest counterexample (and its trace) if one exists.