Generate dummy variable for ranges of data

[bnuss89]

I have a set of data that involves education levels (SCHOOLING) and ages (AGE). I want to generate a dummy variable to indicate whether or not an individual is within two years of the schooling level they should be at for their age. For example if a 9 year old should have 3 years of schooling, I want the dummy variable to be a 1 if they have 1 to 5 years of schooling and a 0 otherwise. How do I create such a dummy variable (AT_LEVEL) to indicate that SCHOOLING is within the range corresponding to AGE?

[Rich Goldstein]

gen byte at_level=inrange(schooling,age-schooling-2,age-schooling+2)

[Svend Juul]

clear
input age schooling
9 0
9 1
9 2
9 3
9 4
9 5
9 6
end
gen at_level = abs(schooling-age+6)<=2

. list, clean

       age   school~g   atlevel 
  1.     9          0         0 
  2.     9          1         1 
  3.     9          2         1 
  4.     9          3         1 
  5.     9          4         1 
  6.     9          5         1 
  7.     9          6         0