Implementing the $\Rightarrow \Leftarrow$ contradiction symbol?

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How is the $\Rightarrow \Leftarrow$ symbol actually used in practice? I think my issue here is that I don't know what the symbol is meant to mean. For example, I know that $\implies$ means "which implies", and $\iff$ means "if and only if" or "iff". What does $\Rightarrow \Leftarrow$ mean? I'm thinking either "a contradiction" or "which implies a contradiction".

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The symbol means nothing more and nothing less than a casual declaration that a contradiction has been reached in an argument/proof. It has no inherent meaning, logically. I've see some use it in classrooms, writing it precisely following the point at which a contradiction has been revealed, as a sort of shorthand.

To be honest, the use of arrows, as in$\Rightarrow \Leftarrow$, is an abuse of notation, in the sense that it has nothing to do with implication, nor reverse implication. I think you're trying to read more into the expression, which is not standard, but rather, shorthand, as suggested in my first paragraph.