See all articles from Syntax/Syntax ZX80 v3 n1
Ian Logan’s 8K Bytes Remaining program, Dec. 81, uses function keywords for all input except E, the numbers, and the punctuation. Thus after 1 REM type the letter E, the numeral 0, the function RND, the function LN, the function arcosine, a colon, and so on. The only space you type in is 1 after the = sign. The second is put in automatically before the GOSUB.