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`and`(d = sqrt(12), sqrt(12) = `+`(`*`(2, `*`(sqrt(3))))) 

`and`(Bd = sqrt(`+`(`+`(`*`(`^`(r, 2)), `*`(`^`(r, 2))), `-`(`*`(`+`(`*`(2, `*`(`^`(r, 2)))), `/`(1, 2))))), `and`(sqrt(`+`(`+`(`*`(`^`(r, 2)), `*`(`^`(r, 2))), `-`(`*`(`+`(`*`(2, `*`(`^`(r, 2)))), `/...