# Test how boolean tests IS TRUE, IS FALSE, get merged into the
# underlying expression.

create table t1(id int, a int);
insert into t1 values(1,1),(2,2),(3,null);
analyze table t1;

# Note that x=y binds tighter than x IS TRUE which binds tighter than NOT x.

explain select id, a=1 is false from t1 ;
select id, a=1 is false from t1 ;

explain select id, not (a=1 is true) from t1 ;
select id, not (a=1 is true) from t1 ;

explain select id, (not a=1) is true from t1 ;
select id, (not a=1) is true from t1 ;

explain select id, not (a=1 is false) from t1 ;
select id, not (a=1 is false) from t1 ;

explain select id, not (a=1 is unknown) from t1 ;
select id, not (a=1 is unknown) from t1 ;

explain select id, ((not a=1) is true) is false from t1 ;
select id, ((not a=1) is true) is false from t1 ;

# Works deeper:
explain select id, 3 + (not (a=1 is false)) from t1 ;
select id, 3 + (not (a=1 is false)) from t1 ;

drop table t1;