test.g4

grammar Test;

root: expr EOF;

expr:
    expr OR expr
  | expr XOR expr
  | expr AND expr
  | INT
;

INT: [0-9]+;
AND: 'and';
XOR: 'xor';
OR: 'or';

WS: (' ' | '\r' | '\n' | '\t') -> skip;

AND should be first. That really should work. could be issue with test!=Test. do you have another file in same dir?

There are no other files in the directory and I'm running this with "grun Test root -tokens -gui" with the input "2 or 3 and 4". With the above grammar the AND is at the top but from what you've said OR should be in the above case because it is the first alternative, correct?

works for me. OR is lowest in tree as it is first precedence, binding it tighter to 2, 3 leaves.

2 or 3 and 4
[@0,0:0='2',<1>,1:0]
[@1,2:3='or',<4>,1:2]
[@2,5:5='3',<1>,1:5]
[@3,7:9='and',<2>,1:7]
[@4,11:11='4',<1>,1:11]
[@5,13:12='<EOF>',<-1>,2:0]
(root (expr (expr (expr 2) or (expr 3)) and (expr 4)) <EOF>)