This means: if we have managed to deduce that a statement is both true and false, then the sequence of deductions show that the pool of assumptions upon which the sequent rests contains assumptions which are mutually contradictory.
Thus, a logical system which includes both of these principles is known as Aristotelian logic.
- Results about Aristotelian logic can be found here.
Source of Name
This entry was named for Aristotle.
- 2000: Michael R.A. Huth and Mark D. Ryan: Logic in Computer Science: Modelling and reasoning about systems ... (previous) ... (next): $\S 1.2.5$: An aside: proof by contradiction