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<H2>Issue TYPE-SPECIFIER-ABBREVIATION Writeup</H2>
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<PRE>Date: Mon, 25 Feb 91 12:18:07 MST<P>
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From: sandra%jensen@cs.utah.edu (Sandra Loosemore)<P>
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<P>
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This is a new version of an issue that was amended and approved at the <P>
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June 1990 meeting. Because there was a lot of confusion about the <P>
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amendment and I am not sure that this revision accurately reflects<P>
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its intent, I think we ought to vote again on proposal <P>
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X3J13-JUN90-GUESS.<P>
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<P>
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<P>
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<B>Issue:</B> <A HREF="iss353.htm">TYPE-SPECIFIER-ABBREVIATION</A><P>
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<B>References:</B> CLtL chapter 4<P>
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<B>Related issues:<P>
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</B><B>Category:</B> CLARIFICATION, CHANGE<P>
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<B>Edit history:</B> V1, 10 May 90, Sandra Loosemore<P>
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V2, 13 Feb 91, Sandra Loosemore (modified proposal)<P>
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<P>
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<P>
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<B>Problem description:<P>
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</B><P>
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Does it make sense for the type specifiers <A REL=DEFINITION HREF="../Body/a_and.htm#and"><B>AND</B></A>, <A REL=DEFINITION HREF="../Body/a_member.htm#member"><B>MEMBER</B></A>, <A REL=DEFINITION HREF="../Body/a_mod.htm#mod"><B>MOD</B></A>, <A REL=DEFINITION HREF="../Body/a_not.htm#not"><B>NOT</B></A>,<P>
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<A REL=DEFINITION HREF="../Body/a_or.htm#or"><B>OR</B></A>, <A REL=DEFINITION HREF="../Body/t_satisf.htm#satisfies"><B>SATISFIES</B></A>, and <A REL=DEFINITION HREF="../Body/a_values.htm#values"><B>VALUES</B></A> (which are documented as list form type<P>
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specifiers in CLtL but omitted from table 4-1) to be abbreviated<P>
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to their atomic form? What about the <A REL=DEFINITION HREF="../Body/a_eql.htm#eql"><B>EQL</B></A> type specifier?<P>
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<P>
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<B>Proposal (TYPE-SPECIFIER-ABBREVIATION:X3J13-JUN90-GUESS):<P>
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</B><P>
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Clarify that:<P>
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<P>
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(1) (<A REL=DEFINITION HREF="../Body/a_and.htm#and"><B>AND</B></A>) is equivalent to type T, but the <A REL=DEFINITION HREF="../Body/a_and.htm#and"><B>AND</B></A> type specifier list <P>
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may not be abbreviated to a type specifier symbol.<P>
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* is not permitted as an argument to the <A REL=DEFINITION HREF="../Body/a_and.htm#and"><B>AND</B></A> type specifier.<P>
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<P>
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(2) The <A REL=DEFINITION HREF="../Body/a_eql.htm#eql"><B>EQL</B></A> type specifier list requires an argument and may not be <P>
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abbreviated to a type specifier symbol.<P>
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* may appear as the argument to an <A REL=DEFINITION HREF="../Body/a_eql.htm#eql"><B>EQL</B></A> type specifier, but it<P>
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indicates the literal symbol *, and does not represent an<P>
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unspecified value.<P>
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<P>
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(3) (<A REL=DEFINITION HREF="../Body/a_member.htm#member"><B>MEMBER</B></A>) is equivalent to type <A REL=DEFINITION HREF="../Body/a_nil.htm#nil"><B>NIL</B></A>, but the <A REL=DEFINITION HREF="../Body/a_member.htm#member"><B>MEMBER</B></A> type specifier list<P>
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may not be abbreviated to a type specifier symbol.<P>
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* may appear as an argument to a <A REL=DEFINITION HREF="../Body/a_member.htm#member"><B>MEMBER</B></A> type specifier, but it<P>
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indicates the literal symbol *, and does not represent an<P>
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unspecified value.<P>
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<P>
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(4) The <A REL=DEFINITION HREF="../Body/a_mod.htm#mod"><B>MOD</B></A> type specifier list requires an argument and may not be<P>
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abbreviated to a type specifier symbol.<P>
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* is not permitted as an argument to the <A REL=DEFINITION HREF="../Body/a_mod.htm#mod"><B>MOD</B></A> type specifier.<P>
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<P>
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(5) The <A REL=DEFINITION HREF="../Body/a_not.htm#not"><B>NOT</B></A> type specifier list requires an argument and may not be<P>
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abbreviated to a type specifier symbol.<P>
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* is not permitted as an argument to the <A REL=DEFINITION HREF="../Body/a_not.htm#not"><B>NOT</B></A> type specifier.<P>
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<P>
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(6) (<A REL=DEFINITION HREF="../Body/a_or.htm#or"><B>OR</B></A>) is equivalent to type <A REL=DEFINITION HREF="../Body/a_nil.htm#nil"><B>NIL</B></A>, but the <A REL=DEFINITION HREF="../Body/a_or.htm#or"><B>OR</B></A> type specifier list<P>
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may not be abbreviated to a type specifier symbol.<P>
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* is not permitted as an argument to the <A REL=DEFINITION HREF="../Body/a_or.htm#or"><B>OR</B></A> type specifier.<P>
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<P>
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(7) The <A REL=DEFINITION HREF="../Body/t_satisf.htm#satisfies"><B>SATISFIES</B></A> type specifier list requires an argument and may not<P>
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be abbreviated to a type specifier symbol.<P>
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* may appear as the argument to a <A REL=DEFINITION HREF="../Body/t_satisf.htm#satisfies"><B>SATISFIES</B></A> type specifier, but it<P>
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indicates the literal symbol *, and does not represent an<P>
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unspecified value.<P>
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<P>
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(8) (<A REL=DEFINITION HREF="../Body/a_values.htm#values"><B>VALUES</B></A>) indicates that no values are returned, but the <A REL=DEFINITION HREF="../Body/a_values.htm#values"><B>VALUES</B></A><P>
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type specifier list may not be abbreviated to a type specifier<P>
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symbol.<P>
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* is not permitted as an argument to the <A REL=DEFINITION HREF="../Body/a_values.htm#values"><B>VALUES</B></A> type specifier.<P>
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<P>
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Rationale for proposal X3J13-JUN90-GUESS:<P>
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<P>
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???<P>
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<P>
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<P>
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<B>Proposal (TYPE-SPECIFIER-ABBREVIATION:NONE):<P>
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</B><P>
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Clarify that the arguments to the <A REL=DEFINITION HREF="../Body/a_and.htm#and"><B>AND</B></A>, <A REL=DEFINITION HREF="../Body/a_eql.htm#eql"><B>EQL</B></A>, <A REL=DEFINITION HREF="../Body/a_member.htm#member"><B>MEMBER</B></A>, <A REL=DEFINITION HREF="../Body/a_mod.htm#mod"><B>MOD</B></A>, <A REL=DEFINITION HREF="../Body/a_not.htm#not"><B>NOT</B></A>, <A REL=DEFINITION HREF="../Body/a_or.htm#or"><B>OR</B></A>, <P>
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<A REL=DEFINITION HREF="../Body/t_satisf.htm#satisfies"><B>SATISFIES</B></A>, and <A REL=DEFINITION HREF="../Body/a_values.htm#values"><B>VALUES</B></A> type specifier lists may not be omitted <P>
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or be given as *. Clarify that these symbols are not <A REL=DEFINITION HREF="../Body/07_ffb.htm#standard"><B>standard</B></A> <P>
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type specifier symbols.<P>
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<P>
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Rationale for proposal NONE:<P>
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<P>
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It's not clear what the abbreviated forms of <A REL=DEFINITION HREF="../Body/a_and.htm#and"><B>AND</B></A>, <A REL=DEFINITION HREF="../Body/a_eql.htm#eql"><B>EQL</B></A>,<P>
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<A REL=DEFINITION HREF="../Body/a_member.htm#member"><B>MEMBER</B></A>, <A REL=DEFINITION HREF="../Body/a_not.htm#not"><B>NOT</B></A>, <A REL=DEFINITION HREF="../Body/a_or.htm#or"><B>OR</B></A>, <A REL=DEFINITION HREF="../Body/t_satisf.htm#satisfies"><B>SATISFIES</B></A>, and <A REL=DEFINITION HREF="../Body/a_values.htm#values"><B>VALUES</B></A> would mean.<P>
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<P>
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While <A REL=DEFINITION HREF="../Body/a_mod.htm#mod"><B>MOD</B></A> could be assigned a reasonable meaning, adding it<P>
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to the list of <A REL=DEFINITION HREF="../Body/07_ffb.htm#standard"><B>standard</B></A> type specifier symbols is a<P>
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pointless change to the language.<P>
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<P>
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<B>Current Practice:<P>
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</B><P>
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Unknown.<P>
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<P>
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<B>Cost to Implementors:<P>
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</B><P>
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Trivial.<P>
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<P>
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<B>Cost to Users:<P>
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</B><P>
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None.<P>
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<P>
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<B>Cost of non-adoption:<P>
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</B><P>
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Part of the language specification will be vague and<P>
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confusing.<P>
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<P>
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<B>Performance impact:<P>
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</B><P>
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None.<P>
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<P>
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<B>Benefits:<P>
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</B><P>
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Part of the language specification will be made more precise.<P>
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<P>
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<B>Esthetics:<P>
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</B><P>
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Seems to be a matter of personal taste.<P>
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<P>
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<B>Discussion:<P>
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</B><P>
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Proposal NONE was accepted at the June 1990 meeting with the following<P>
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amendment, replacing the first paragraph of the proposal:<P>
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<P>
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Clarify certain type specifiers as follows:<P>
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(<A REL=DEFINITION HREF="../Body/a_and.htm#and"><B>AND</B></A>) is equivalent to T.<P>
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(<A REL=DEFINITION HREF="../Body/a_member.htm#member"><B>MEMBER</B></A>) is equivalent to <A REL=DEFINITION HREF="../Body/a_nil.htm#nil"><B>NIL</B></A><P>
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(<A REL=DEFINITION HREF="../Body/a_or.htm#or"><B>OR</B></A>) is equivalent to <A REL=DEFINITION HREF="../Body/a_nil.htm#nil"><B>NIL</B></A>.<P>
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<A REL=DEFINITION HREF="../Body/a_and.htm#and"><B>AND</B></A>, <A REL=DEFINITION HREF="../Body/a_eql.htm#eql"><B>EQL</B></A>, <A REL=DEFINITION HREF="../Body/a_member.htm#member"><B>MEMBER</B></A>, <A REL=DEFINITION HREF="../Body/a_mod.htm#mod"><B>MOD</B></A>, <A REL=DEFINITION HREF="../Body/a_not.htm#not"><B>NOT</B></A>, <A REL=DEFINITION HREF="../Body/a_or.htm#or"><B>OR</B></A>, <A REL=DEFINITION HREF="../Body/t_satisf.htm#satisfies"><B>SATISFIES</B></A>, and <A REL=DEFINITION HREF="../Body/a_values.htm#values"><B>VALUES</B></A> type<P>
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specifiers may not be abbreviated to type specifiers that<P>
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are symbols.<P>
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<A REL=DEFINITION HREF="../Body/a_and.htm#and"><B>AND</B></A>, <A REL=DEFINITION HREF="../Body/a_not.htm#not"><B>NOT</B></A>, <A REL=DEFINITION HREF="../Body/a_or.htm#or"><B>OR</B></A> and <A REL=DEFINITION HREF="../Body/a_values.htm#values"><B>VALUES</B></A> type specifiers may not take * as<P>
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an argument (i.e., as an unspecified type)<P>
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<P>
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Taken literally, this amendment leaves some questions unanswered,<P>
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such as whether (<A REL=DEFINITION HREF="../Body/a_eql.htm#eql"><B>EQL</B></A>) is meaningful or what (<A REL=DEFINITION HREF="../Body/a_eql.htm#eql"><B>EQL</B></A> *) might mean.<P>
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Proposal X3J13-JUN90-GUESS is my attempt at guessing what the amendment<P>
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was really trying to say.<P>
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<P>
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Loosemore thinks that we ought to make <A REL=DEFINITION HREF="../Body/a_mod.htm#mod"><B>MOD</B></A> == (<A REL=DEFINITION HREF="../Body/a_mod.htm#mod"><B>MOD</B></A>) == (<A REL=DEFINITION HREF="../Body/a_mod.htm#mod"><B>MOD</B></A> *) ==<P>
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(integer 0 (*)) == <A REL=DEFINITION HREF="../Body/t_unsgn_.htm#unsigned-byte"><B>UNSIGNED-BYTE</B></A>, but everybody else seems to hate<P>
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the idea.<P>
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</PRE>
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