Parsed test spec with 2 sessions

starting permutation: s1as s2as s1ae s2ae s1c s2c
step s1as: LOCK TABLE a1 IN ACCESS SHARE MODE;
step s2as: LOCK TABLE a1 IN ACCESS SHARE MODE;
step s1ae: LOCK TABLE a1 IN ACCESS EXCLUSIVE MODE; <waiting ...>
step s2ae: LOCK TABLE a1 IN ACCESS EXCLUSIVE MODE;
step s1ae: <... completed>
error in steps s2ae s1ae: ERROR:  deadlock detected
step s1c: COMMIT;
step s2c: COMMIT;