ADS version : ads-windows-x64-14.0.0-alpha-18
Database:Sybase ASE 15.7.

create table employee_sybase
(ID SMALLINT NOT NULL,
NAMEa VARCHAR(9) ,
DEPT SMALLINT,
JOB CHAR(5) CHECK (JOB IN ('Sales', 'Mgr', 'Clerk')),
HIREDATE DATE,
LEVDATE DATE,
SALARY DECIMAL(7,2),
COMM DECIMAL(7,2),
PRIMARY KEY (ID),
CONSTRAINT yearsal CHECK ((HIREDATE > LEVDATE) OR (SALARY > 40500)),
constraint deptid CHECK (DEPT BETWEEN 10 AND 100) )

create table employee_sybase
(ID SMALLINT NOT NULL,
NAMEa VARCHAR(9) CHECK (NAMEa IN ('Sales', 'Mgr', 'Clerk')) ,
DEPT SMALLINT,
JOB CHAR(5) CHECK (JOB IN ('Sales', 'Mgr', 'Clerk')),
HIREDATE DATE,
LEVDATE DATE,
SALARY DECIMAL(7,2),
COMM DECIMAL(7,2),
PRIMARY KEY (ID),
CONSTRAINT yearsal CHECK ((HIREDATE > LEVDATE) OR (SALARY > 40500)),
constraint deptid CHECK (DEPT BETWEEN 10 AND 100)).

Go to Tools->Compare Tools->Schema compare->Choose server1 and server2 as Syabse ASE-> Select respective table and schema values from list and from options select all options.

Now in result look for system generated constraint names you will see that there will be "double" check keyword. Where we have given constraint names there will be only single check constraint keyword.