FAC ::= APPLY | (APPLIER (MUL | DIV) APPLY)
APPLY ::= "(" ID APPLYEE* ")" | APPLYEE
APPLYEE ::= REF | CONST | EXPR | FUNC
-CONST ::= INT | STR | FLO | BOOL
+* CONST ::= INT | STR | FLO | BOOL
BOOL ::= "true" | "false"
FUNC ::= FUNC_OPTION? ( ARGS? ) -> TYPE {BLOCK}
BLOCK ::= PROG (return ID |noReturn) ;