set enable_seqscan=off;
CREATE TABLE test_bool (
	i boolean
);
INSERT INTO test_bool VALUES (false),(true),(null);
CREATE INDEX idx_bool ON test_bool USING gin (i);
SELECT * FROM test_bool WHERE i<true ORDER BY i;
 i 
---
 f
(1 row)

SELECT * FROM test_bool WHERE i<=true ORDER BY i;
 i 
---
 f
 t
(2 rows)

SELECT * FROM test_bool WHERE i=true ORDER BY i;
 i 
---
 t
(1 row)

SELECT * FROM test_bool WHERE i>=true ORDER BY i;
 i 
---
 t
(1 row)

SELECT * FROM test_bool WHERE i>true ORDER BY i;
 i 
---
(0 rows)

SELECT * FROM test_bool WHERE i<false ORDER BY i;
 i 
---
(0 rows)

SELECT * FROM test_bool WHERE i<=false ORDER BY i;
 i 
---
 f
(1 row)

SELECT * FROM test_bool WHERE i=false ORDER BY i;
 i 
---
 f
(1 row)

SELECT * FROM test_bool WHERE i>=false ORDER BY i;
 i 
---
 f
 t
(2 rows)

SELECT * FROM test_bool WHERE i>false ORDER BY i;
 i 
---
 t
(1 row)

EXPLAIN (COSTS OFF) SELECT * FROM test_bool WHERE i<true ORDER BY i;
                QUERY PLAN                 
-------------------------------------------
 Sort
   Sort Key: i
   ->  Bitmap Heap Scan on test_bool
         Recheck Cond: (i < true)
         ->  Bitmap Index Scan on idx_bool
               Index Cond: (i < true)
(6 rows)

EXPLAIN (COSTS OFF) SELECT * FROM test_bool WHERE i<=true ORDER BY i;
                QUERY PLAN                 
-------------------------------------------
 Sort
   Sort Key: i
   ->  Bitmap Heap Scan on test_bool
         Recheck Cond: (i <= true)
         ->  Bitmap Index Scan on idx_bool
               Index Cond: (i <= true)
(6 rows)

EXPLAIN (COSTS OFF) SELECT * FROM test_bool WHERE i=true ORDER BY i;
         QUERY PLAN          
-----------------------------
 Sort
   Sort Key: i
   ->  Seq Scan on test_bool
         Filter: i
(4 rows)

EXPLAIN (COSTS OFF) SELECT * FROM test_bool WHERE i>=true ORDER BY i;
                QUERY PLAN                 
-------------------------------------------
 Sort
   Sort Key: i
   ->  Bitmap Heap Scan on test_bool
         Recheck Cond: (i >= true)
         ->  Bitmap Index Scan on idx_bool
               Index Cond: (i >= true)
(6 rows)

EXPLAIN (COSTS OFF) SELECT * FROM test_bool WHERE i>true ORDER BY i;
                QUERY PLAN                 
-------------------------------------------
 Sort
   Sort Key: i
   ->  Bitmap Heap Scan on test_bool
         Recheck Cond: (i > true)
         ->  Bitmap Index Scan on idx_bool
               Index Cond: (i > true)
(6 rows)