Compiler for "Easy" language from "Etudes for Programmers" book (1978) (github.com)

I was assuming it's something similar to PL/0 but the grammar looks quite extensive...

The "FI" for "endif" is like bash.

The semicolons are like C.

The "PROGRAM" section is like COBOL.

The Etudes book is considered a classic, especially among FSU programmers-the book was licensed for a small amount, translated into Russian and used in many classrooms.