[AaronFriel]

Math degree holder from Iowa, yeah, I've seen and used it many times. The symbol is used when you reach the contradictory statement. Like "1 = 2".

"By way of contradiction suppose P, then ..., thus ~P ↯. Therefore ..."

[nerdponx]

I've actually always wanted a way to mark "the contradiction" once I've obtained it. Thanks!

[phogster]

To me that reads: I throw your assumption into the GROUND!