The +syntax meta specifies the version of the EO language that
the source code was written for. If the parser version is older
than the version specified in +syntax, the code may use features
that are not supported by the parser, leading to compilation errors.
The parser will refuse to process such files.
Incorrect (if parser version is 0.58.0):
+syntax 0.59.0
[] > foo
Correct (if parser version is 0.59.0 or newer):
+syntax 0.59.0
[] > foo