= Double-precision floating-point format
{title2=binary64}
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= binary64
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= Double precision
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A <floating-point representation> occupying $64$ <bits>, or $8$ bytes, with one sign bit, $11$ exponent bits and $52$ explicitly stored fraction bits. The implicit leading bit of a normal number gives $53$ bits of significand precision. Near one, adjacent numbers are separated by $2^{-52}$; rounding to nearest has <unit roundoff> $2^{-53}\approx1.11\times10^{-16}$ in the normal range. These are relative precision scales, distinct from underflow limits or a universal absolute error bound.<IEEE arithmetic in Oracle's Numerical Computation Guide>[Chapter 2, IEEE Arithmetic Model and Double Format, Table 2-5]{ref}
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