Excerpts from Knight v. Hallsthammar (1981), 29 Cal.3d 46(expands on Green v. Superior) - GIVES TENANTS RIGHT TO REDUCE/WITHHOLD RENT RE HABITABILITY ISSUES. "[t]he landlord's lack of fault and reasonable efforts to repair do not prolong the duty to pay full rent."..."At least in a situation where, as here, a landlord has notice of alleged uninhabitable conditions not caused by the tenants themselves, a landlord's breach of the implied warranty of habitability exists whether or not he has had a "reasonable" time to repair. Otherwise, the mutual dependence of a landlord's obligation to maintain habitable premises, and of a tenant's duty to pay rent, would make no sense. "public policy requires that the implied warranty "generally could not be waived by any provision in the rental agreeme"The same reasons which imply the existence of the warranty of habitability -- the inequality of bargaining power, the shortage of housing, and the impracticability of imposing upon tenants a duty of inspection -- also compel the conclusion that a tenant's lack of knowledge of defects is not a prerequisite to the landlord's breach of the warranty".