The court made comparative observations about the treatment of agreements to negotiate in good faith in other legal systems: English, Irish and Scots law generally refuse to recognize pre-contractual duties to negotiate in good faith. In the United States, enforceability varies by state, with some courts refusing enforcement on grounds of indefiniteness while others give effect to parties' expressed intentions (the latter view gaining substantial following). European courts (particularly German, French, Italian and Belgian) have been more receptive to pre-contractual liability based on good faith obligations. Australian law, as exemplified in Coal Cliff Collieries, takes the view that certainty is the touchstone of enforceability, with enforceability depending on the construction of the particular contract. The court noted that the duty to negotiate in good faith is well-established in South African labour law as fundamental to collective bargaining, and while the analogy to ordinary contract negotiations is imperfect, useful comparisons can be drawn. The court also observed that the nature of use and enjoyment of leased property usually flows from the nature of the property itself and is often dictated by external factors such as zoning.