%set(name,xin)
%set(syntax,%%xin(string[\,str1[\,str2[\,...]]]))
%set(description,Determines if string is equal to any of the other string parameters str1\, 
str2\,.... Returns T if it is\, and %%null%% otherwise. %%in() performs case-
insensitive comparisons; %%xin() performs case-sensitive comparisons. 

- Parameter expansion will stop at the first parameter that matches string. 

- This preserves short-circuit evaluation semantics.)
%set(author,)
%set(example,%%xin('ca\,'CA\,'Ca\,'cA) => %%null%% 
%%if(%%xin('ca\,'CA\,'Ca\,'cA)\,'Yes\,'No))
%set(seealso,)
