Mistakes and Ambiguities in the De nition of Standard ML

The De nition of Standard ML contains several errors and ambiguities Some of them have already been published in the Commentary on Standard ML but the list given there is incomplete The paper lists all errors known to me today including the errors listed in the Commentary On most of the others I came across when writing the semantics of Extended ML Most errors are supplied with an explanation what goes wrong and with a suggested correction I understand error in a very broad sense ranging from typos to serious aws in the rules Some of the problems I mention are originated by a certain tension between formal de nitions and informal ex planations e g overloading is informally explained though impossible in the given formal setting Some parts of the paper are di cult to understand without prior knowledge of the De nition and the Commentary because I rely on the notation and jargon introduced in these books However the nature of this paper has it that the various sections do not depend on each other making it possible for somebody not familiar with the entrails of SML to read the less technical sections on their own Structure of the Paper I have divided the errors into the classes Errors Listed in the Commentary and Further Errors This is by no means a conceptual distinction It simply gives a quicker answer to the question What s new for the lucky owners of the Commentary Here and in the following the De nition always refers to MTH the Commentary to MT Within the two parts the errors are listed in the same order as they appear in the De nition References of the form line n refer to the nth line from the bottom of the corresponding page or section The research reported here was partially supported by SERC grant GR E Part I Errors Listed in the Commentary All errors described in this part are mentioned in the Commentary Not all corrections proposed in the Commentary are entirely satisfactory this is also discussed Some of the quotations from the Commentary refer to certain Sections these are sections of the Commentary itself