> Some of the computer scientists, however, instinctively interpreted the statement “Let x be such that P(x)” as a variable declaration. This led them to give a

> Some of the computer scientists, however, instinctively interpreted the statement “Let x be such that P(x)” as a variable declaration. This led them to give an “incorrect” answer to a question "Let x be such that P(x)" is something like a variable declaration. It's the introduction of an argument to a function (think "function(x){ ... }"). I think the real conceptual problem lies in the fact that many mainstream programming languages allow subversion of the type system by allowing "uninitialized" variables, so that every type is automatically inhabited. There is also the fact that a mathematician may just want some "x such that P(x)" rather than introducing a generic one, which I think the author mentions.