:FROM-END
** ELT signals an error of type TYPE-ERROR when the index argument
is not a valid sequence index;
+ ** LOOP signals (at macroexpansion time) an error of type
+ PROGRAM-ERROR when duplicate variable names are found;
* fixed bug 166: compiler preserves "there is a way to go"
invariant when deleting code.
* fixed bug 172: macro lambda lists with required arguments after