sysuse nlsw88, clear
gen ed = cond(grade< 12, 1, ///
         cond(grade==12, 2, ///
         cond(grade<16,3,4))) if grade < .
gen byr = (1988-age-1950)/10
gen white = race == 1 if race < .

seqlogit ed byr south,                   ///   
         ofinterest(white) over(byr)     ///
         tree(1 : 2 3 4, 2 : 3 4, 3 : 4) ///
         levels(1=6, 2=12, 3=14, 4= 16)  ///
         or pr(.25 .25 .25 .25) sd(1 1.5 2) 
    
uhdesc