"12. (2) The decision of a tribunal, which may be given orally at the end of a hearing or reserved, shall be recorded in a document signed by the chairman." (3) The tribunal shall give reasons for its decision in a document signed by the chairman… "30. In my judgment, however, Mummery J was correct when at 11B of the transcript of his judgment he said that there was nothing in the principles of cause of action or issue estoppel which stipulated that they could only apply in cases where a tribunal has given a reasoned decision on the issues of fact and law in the previous litigation. Section 140 of the 1978 Act contains provisions which render void any agreement to preclude a person from bringing proceedings before an industrial tribunal. A tribunal has therefore to be satisfied that a withdrawal is properly made. 31. I am satisfied that the order which was made by the industrial tribunal on5 May 1993 was a judicial decision made by the industrial tribunal in the exercise of its powers under the 1978 Act and the 1985 Regulations. It was not a mere administrative act."