13. Not only the plea has to be taken, it has to be substantiated by producing the copies of the pleadings, issues and judgment in the previous case. May be in a given case only copy of judgment in previous suit is filed in proof of plea of res judicata and the judgment contains exhaustive or in requisite details the statement of pleadings and the issues which may be taken as enough proof. But as pointed out in Syed Mohd. Salie Labbai (Dead) By Lrs. & Ors. Vs. Mohd. Hanifa (Dead) by Lrs. & Ors. � (1976) 4 SCC 780, the basic method to decide the question of res judicata is first to determine the case of the parties as put forward in their respective pleadings of their previous suit and then to find out as to what had been decided by the judgment which operates as res judicata. It is risky to speculate about the pleadings merely by a summary of recitals of the allegations made in the pleadings mentioned in the judgment. The Constitution Bench in Gurbux Singh Vs. Bhooralal � (1964) 7 SCR 831, placing on a par the plea of res judicata and the plea of estoppel under Order II Rule 2 of the Code of Civil Procedure, held that proof of the plaint in the previous suit which is set to create the bar, ought to be brought on record. The plea is basically founded on the identity of the cause of action in the two suits and, therefore, it is necessary for the defence which raises the bar to establish the cause of action in the previous suit. Such pleas cannot be left to be determined by mere speculation or inferring by a process of deduction
