ekra fu'ivla

x1 is the informational viewing area of output device x2

In notes:

vidnyja'o
j1=v1 (video monitor/screen) displays j2 to j3; j2 is the display of monitor j1=v1 shown to j3.
tekla
x1 is a button/key (of piano, typewriter, computer) causing event x2 (property of x1)