Abstract
Mathematicians frequently use probabilistic language when discussing statements that have not yet been proved or disproved : one statement is " almost certainly true ", another is " unexpected ", and a third " could possibly be true but there is probably a counterexample ". Given that (decidable) mathematical statements have deterministic truth values, the use of this language may seem somewhat paradoxical. This seminar looked at several examples of unsolved problems and the reasons mathematicians have given to justify their beliefs about solutions that have not yet been found.
