XCAS float precision

[Albert Chan]

I finally join the club, and downloaded XCas (for Windows 32-bits)

If XCas float default is IEEE double precision, I should get this:

Python: 3.141592653589794 - 3.141592653589793 => 8.88e-16

This is above in hex-float, where ULP = 2^-51 ~ 4.44e-16:
0x1.921fb54442d1aP1 - 0x1.921fb54442d18P1 = 2 ULP ~ 8.88e-16

Instead, I get something unexpected, suggesting XCas uses 54-bits float (or more)
(Also, returned float is not normalized, with a zero before decimal point)

XCAS: 3.141592653589794 - 3.141592653589793 => 0.111e-14 (2.5 ULP ?)

Just to confirm above with 54-bits float math (now, ULP = 2^-52)

0x1.921fb54442d1a0P+1 - 0x1.921fb54442d178P+1 = 5 ULP ~ 1.11E-15 (match above)