ROOT ::= EXPR*

INSTR ::=
| EXPR semicolon

EXPR ::=
| OR
| ASSERT EXPR

OR ::= AND (or AND)*
AND ::= EQNE (and EQNE)*
EQNE ::= CMP ((eq|ne) CMP)?
CMP ::= TERM ((lt|le|gt|ge) TERM)?
TERM ::= FACTOR ((add|sub) FACTOR)*
FACTOR ::= POW ((mul|div|mod) POW)*
POW ::= NOT (pow NOT)?

NOT ::= not* LITERAL
LITERAL ::= BUILTIN | opar EXPR cpar
BUILTIN ::= bool | int | float | string