Only a certain type of character may be used as a
delimiter (for example,
( ) [ ]), check which one you have specified. This error may
also occur if you have forgotten a
\right or not used it in the
(Remember to use a . if you want an invisible delimiter) or
you may have forgotten to end your array environment with
This book is also available as A4 PDF or 12.8cm x 9.6cm PDF or paperback (ISBN 978-1-909440-00-5).