问SAS函数中缺少的操作符在哪里？

EN

%GLOBAL nBlue = 0;
%GLOBAL nRed = 0;

%MACRO GetArmySizes(redData=, blueData=);
/* Takes in 2 Army Datasets, and outputs their respective sizes to nBlue and nRed */

    data _Null_;
        set &blueData nobs=j;
        if _N_ =2 then stop;
        No_of_obs=j;
        call symput("nBlue",j);
    run;

    data _Null_;
        set &redData nobs=j;
        if _N_ =2 then stop;
        No_of_obs=j;
        call symput("nRed",j);
    run;
    %put &nBlue;
    %put &nRed;
%MEND;

%put &nBlue; /* outputs 70 here */
%put &nRed; /* outputs 100 here */

%put %EVAL(min(1,5));

%GetArmySizes(redData=redTeam1, blueData=blueTeam); /* outputs 70\n100 here */

%put &nBlue; /* outputs 70 here */
%put &nRed; /* outputs 100 here */

%MACRO PrepareOneVOneArmies(redData=,numRed=,blueData=,numBlue=);
/* Takes in two army data sets and their sizes, and outputs two new army
   data sets with the same number of observations */

    %let smallArmy = %eval(min(&numRed,&numBlue));
    %put &smallArmy;

    %local numOneVOne;
    %let numOneVOne = %eval(&smallArmy-%Eval(&nBlue - &nRed));
    %put &numOneVOne;

    data redOneVOne; set &redData (obs=&numOneVOne);
    run;

    data blueOneVOne; set &blueData (obs=&numOneVOne);
    run;
%MEND;

%PrepareOneVOneArmies(redData=redTeam1,numRed=&nRed,blueData=blueTeam,numBlue=&nBlue); 
/* stops executing when program gets to  %let smallArmy =... */