@Override public VarUsage count(final Var v) { final VarUsage inPreds = super.count(v), inRoot = root.count(v); if (inPreds == VarUsage.NEVER) return inRoot; final long sz = root.size(); return sz >= 0 && sz <= 1 || root.type().zeroOrOne() ? inRoot.plus(inPreds) : VarUsage.MORE_THAN_ONCE; }