simultaneous keystrokes
akordvajutus
olemus
mitme klahvi korraga vajutamine
(a) juhusliku sisestusveana
https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.1080.6839&rep=rep1&type=pdf
(b) klaviatuuri erivõimalusena sisestuse kiirendamiseks
https://stackoverflow.com/questions/20871605/implementing-simultaneous-keystrokes-for-game
vt ka
https://en.wikipedia.org/wiki/Rollover_(key)
https://en.wikipedia.org/wiki/Modifier_key