2787	 Matrix Reduction-An Efficient Method	 The paper describes an efficient method for reduction of the binary matrices which arise in some school time-tabling problems. It is a development of that described by John Lions. It has been generalized and adapted to fit into the complete timetabling process to use a more compact data representation and more efficient processing techniques to take fuller advantage of possible available previous knowledge about the matrix. And it is designed as a structured program which can readily be coded by the reader in the high level or low level programming language of his choice. Practical tests of the method have shown it to be a good basis for a realistic timetabling algorithm. binary matrices matrix reduction tight set school timetable construction structured programming
