The Law of Sufficlent Reason is an Important Law of Formal Logic

Just recently I read carefully the article by Comrades Lin Mingjun et al., "The law of sufficient reason is not a fundamental law of formal logic," and the article of Comrade Li Xiankun, "The place and function of the law of sufficient reason in formal logic." (These two articles will be referred to below as "Lin's article" and "Li's article" respectively. Both articles are from Zhexue Yanjiu [Philosophical Research], 1979, No. 3.) The present article contains some of our disagreements with the above two articles.