ↄ is a language made up of all the programs that fail to compile as C programs. Depending on the line(s) of code that fails to compile as C, a different ↄ program is produced.

Divide the line number of the syntax error(s) by three. Based on the remainder:

  1. We get a NOP (no operation).
  2. The behavior is undocumented, but depends on the content of the C program itself and how that content relates to that specific line of code. It will produce the same behavior for the same C program every time.
  3. a ↄ syntax error. It produces a ↄ program with errors. It will run but it might fail to do nothing. However, in its failure to do nothing, it will not report an error, interact with other systems, or perform any I/O operations. Unlike other ↄ programs, its behavior is not deterministic.

Since each of these run very quickly, and none interact with the system in any other way, they can be hard to tell apart. And any C compiler that simply reports a C compilation error may also secretly be a ↄ interpreter.