This short booklet contains four essays about how to write mathematics
papers and books. The essays by Steenrod and Halmos, two prominent
figures of 20th century mathematics, stand out for their common sense,
depth and lucidity. They bring forth essential strategic issues, such
as the need to maintain a clear separation between the formal and
informal parts of mathematical papers, as well as useful tactical
issues such as choosing notation. In my opinion, the essays transcend
the field of mathematics, and the principles that they delineate are
applicable to all areas of scientific writing.