This seems to be fixed in apcalc 2.12.5.0, to be uploaded to unstable shortly:
C-style arbitrary precision calculator (version 2.12.5.0) Calc is open software. For license details type: help copyright [Type "exit" to exit, or "help" for help.] ; display(70) 20 ; for (n = 4 ; n <= 70 ; n += 4) { epsilon(10^(-n)) ; print n, log(10^0.5) ; } 4 0.5 8 ~0.5000000021714724123398193288917718128714192273346128546328769982611153 12 0.5 16 ~0.4999999999999999782852759048374087681632417234746140129701972730600964 20 0.5 24 ~0.5000000000000000000000002171472409516259138255645023376973100683865400 28 ~0.4999999999999999999999999999782852759048374086174435540543172005522040 32 0.5 36 0.5 40 ~0.5000000000000000000000000000000000000000217147240951625913825564459458 44 ~0.4999999999999999999999999999999999999999999978285275904837408617443554 48 ~0.4999999999999999999999999999999999999999999999997828527590483740861744 52 0.5 56 ~0.5000000000000000000000000000000000000000000000000000000021714724095163 60 0.5 64 0.5 68 ~0.4999999999999999999999999999999999999999999999999999999999999999999978 ; for (n = 4 ; n <= 70 ; n += 4) { epsilon(10^(-n)) ; print n, 0.5 - log(10^0.5) ; } 4 0 8 ~-0.0000000021714724123398193288917718128714192273346128546328769982611153 12 0 16 ~0.0000000000000000217147240951625912318367582765253859870298027269399036 20 0 24 ~-0.0000000000000000000000002171472409516259138255645023376973100683865400 28 ~0.0000000000000000000000000000217147240951625913825564459456827994477960 32 0 36 0 40 ~-0.0000000000000000000000000000000000000000217147240951625913825564459458 44 ~0.0000000000000000000000000000000000000000000021714724095162591382556446 48 ~0.0000000000000000000000000000000000000000000000002171472409516259138256 52 0 56 ~-0.0000000000000000000000000000000000000000000000000000000021714724095163 60 0 64 0 68 ~0.0000000000000000000000000000000000000000000000000000000000000000000022 -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org