Door _R0N_:
Zover ik weet is er maar 1x bevestigd dat het 100% zeker is dat er geen bugs zitten in een stuk software. Dat stukje software, wat niet heel complex is was de originele Pacman.
De originele Pacman _heeft_ een bug.
https://errors.fandom.com/wiki/Pac_Man_-_Infamous_Kill_Screen_BugEr is research naar formele verificatie
https://en.wikipedia.org/wiki/Formal_verification(dat gaat natuurlijk all the way down - met bewezen compiler, op bewezen hardware ...)
Avionics software is een gebied wat misschien niet bewezen bugvrij is, maar wel _extreem_ weinig bugs.
Feynman in de beschrijving van de Space Shuttle.
(
https://www.ranum.com/security/computer_security/editorials/dumb/feynman.htmlDonald Knuth heeft ook wat (significante) software geschreven met _erg_ weinig bugs :
The original source code for the current TeX software is written in WEB, a mixture of documentation written in TeX and a Pascal subset in order to ensure readability and portability. For example, TeX does all of its dynamic allocation itself from fixed-size arrays and uses only fixed-point arithmetic for its internal calculations. As a result, TeX has been ported to almost all operating systems, usually by using the web2c program to convert the source code into C instead of directly compiling the Pascal code. Knuth has kept a very detailed log of all the bugs he has corrected and changes he has made in the program since 1982; as of 2021, the list contains 440 entries, not including the version modification that should be done after his death as the final change in TeX.[40][41] Knuth offers monetary awards to people who find and report a bug in TeX. The award per bug started at US$2.56 (one "hexadecimal dollar"[42]) and doubled every year until it was frozen at its current value of $327.68. Knuth has lost relatively little money as there have been very few bugs claimed. In addition, recipients have been known to frame their cheque as proof that they found a bug in TeX rather than cashing it.[43][44]
Due to scammers finding scanned copies of his checks on the internet and using them to try to drain his bank account, Knuth no longer sends out real checks, but those who submit bug reports can get credit at The Bank of San Serriffe instead.[45]