The double equal sign for testing equality, used above, is brittle and can give unintended results due to the limited precision of representing numbers in the computer’s memory. For example, in most computers, the value of 0.5 − 0.3 does not equal the value of 0.3 − 0.1, even though mathematically they are equivalent. Therefore, R has another function, all.equal, for testing equality up to the degree of precision for the computer being used.