create table t1(id int, a int);
insert into t1 values(1,1),(2,2),(3,null);
analyze table t1;
Table	Op	Msg_type	Msg_text
test.t1	analyze	status	OK
explain select id, a=1 is false from t1 ;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t1	NULL	ALL	NULL	NULL	NULL	NULL	3	100.00	NULL
Warnings:
Note	1003	/* select#1 */ select `test`.`t1`.`id` AS `id`,((`test`.`t1`.`a` = 1) is false) AS `a=1 is false` from `test`.`t1`
select id, a=1 is false from t1 ;
id	a=1 is false
1	0
2	1
3	0
explain select id, not (a=1 is true) from t1 ;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t1	NULL	ALL	NULL	NULL	NULL	NULL	3	100.00	NULL
Warnings:
Note	1003	/* select#1 */ select `test`.`t1`.`id` AS `id`,((`test`.`t1`.`a` = 1) is not true) AS `not (a=1 is true)` from `test`.`t1`
select id, not (a=1 is true) from t1 ;
id	not (a=1 is true)
1	0
2	1
3	1
explain select id, (not a=1) is true from t1 ;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t1	NULL	ALL	NULL	NULL	NULL	NULL	3	100.00	NULL
Warnings:
Note	1003	/* select#1 */ select `test`.`t1`.`id` AS `id`,((`test`.`t1`.`a` <> 1) is true) AS `(not a=1) is true` from `test`.`t1`
select id, (not a=1) is true from t1 ;
id	(not a=1) is true
1	0
2	1
3	0
explain select id, not (a=1 is false) from t1 ;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t1	NULL	ALL	NULL	NULL	NULL	NULL	3	100.00	NULL
Warnings:
Note	1003	/* select#1 */ select `test`.`t1`.`id` AS `id`,((`test`.`t1`.`a` = 1) is not false) AS `not (a=1 is false)` from `test`.`t1`
select id, not (a=1 is false) from t1 ;
id	not (a=1 is false)
1	1
2	0
3	1
explain select id, not (a=1 is unknown) from t1 ;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t1	NULL	ALL	NULL	NULL	NULL	NULL	3	100.00	NULL
Warnings:
Note	1003	/* select#1 */ select `test`.`t1`.`id` AS `id`,((`test`.`t1`.`a` = 1) is not null) AS `not (a=1 is unknown)` from `test`.`t1`
select id, not (a=1 is unknown) from t1 ;
id	not (a=1 is unknown)
1	1
2	1
3	0
explain select id, ((not a=1) is true) is false from t1 ;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t1	NULL	ALL	NULL	NULL	NULL	NULL	3	100.00	NULL
Warnings:
Note	1003	/* select#1 */ select `test`.`t1`.`id` AS `id`,((`test`.`t1`.`a` <> 1) is not true) AS `((not a=1) is true) is false` from `test`.`t1`
select id, ((not a=1) is true) is false from t1 ;
id	((not a=1) is true) is false
1	1
2	0
3	1
explain select id, 3 + (not (a=1 is false)) from t1 ;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t1	NULL	ALL	NULL	NULL	NULL	NULL	3	100.00	NULL
Warnings:
Note	1003	/* select#1 */ select `test`.`t1`.`id` AS `id`,(3 + ((`test`.`t1`.`a` = 1) is not false)) AS `3 + (not (a=1 is false))` from `test`.`t1`
select id, 3 + (not (a=1 is false)) from t1 ;
id	3 + (not (a=1 is false))
1	4
2	3
3	4
drop table t1;