Resignation during probation

Probation is for seeing ones conduct during that time and then regularising the person

If in your Appointment letter , no condition is stipulated , neither you have given undertaking of any kind , you can resign instantly and no action will take place

But ITS RARE THAT THERE IS NEITHER ANY CONDITIONS IN APPOINTMENT LETTER FOR YOUR LEAVING THE JOB ABRUPTLY OR ALSO AN OBLIQUE REFERENCE THAT YOUR SERVICE WILL BE GIVERENED IN ACCORDANCE WITH SUCH AND SUCH RULES, REGULATIONS ,  CONDUCT RULES , OR UNDERTAKING WHICH YOU HAVE GIVEN ETC ETC 

        SO pl clarify

       (i) There is no such oblique reference as obove in your Appt Letter

       (ii) You have not given any undertaking before apptt

      With regards ,